Alright here's my heartfelt contribution with regards to this control arm issue.
Disclaimer; i might not be totally right in aspects of technical know how, but i know what fits and what doesn't.
Front LCAs first. Now what fits, what doesn't.
FTO
Direct bolt on?
Yes, your current knuckles will fit in snug. Or you can even get FTO knuckles and go 5 lug.
Worth it ?
No, IMHO. Are they wider? Not sure. But seriously if you want a wider track, just slap on wider and lower offset wheels. And if you think they help your handling better, I will tell you straight in the face no. FTO lcas are pressed steel arms but thats besides the point. I don't think aluminium arms will yield you any better handling if any @ all. Material that your LCAs are made of is 1 issue if it even is an issue, your LCA lower front and rear bushings contribute to handling difference too. In this case of the FTO. the bushings are the SAME as any CA-CC, CE Mirage. And yes, i know for a fact they carry the same part numbers. For those that are doubtful, you are free to double tally on the SuperPro website.
Evo 45, even 6
Direct bolt on?
Yes and no. You will also need Evo knuckles to go. And Evo Tie rod ends. Not sure if you need the steering rods. Becoz of some turning angle on the Evo knuckles. Usage of OE Mirage tie rod ends will invite bump steer to kingdom come. Or something. I can't quite rmbr.
Worth it? : No. Yes they are aluminum construction. Yes they are stronger. Not sure if they are lighter. But that doesn't necessarily mean better handling. Too much trouble for too little gain.
In theory there are 3 benefits of Evo arms;
1st, is the is that they have added castor. But they also make your wheels seat more towards the front of your wheel arches. Not sure if anyone will benefit from this as this may contribute to wheel rub in front. Unless you are chasing the epitome of lap times or even running some big power output... or else really...
2nd, the knuckles you are forced to run with because of the different ball joint design (i read somewhere that it can be pressed out and replaced with something that will fit OE CE knuckles but information on which ball joint and what part number is non existent. But really why bother) for Evo arms run a 1 piece hub and bearing design unlike the ones we find in anything CE and older, even the older EVO123s. More lasting and durable and lesser prone to failure, or longer time in between failures?
Ahah. So therein lies a problem. you can't use the hub and bearings from the CE and older as bearing and hub are separate. Which means you are stuck with using 5x114.3, or you source the 1pc bearing/hub in 4x100 or 4x114.3 that came with JDM (CE) Mirage Cyborg RS cars, which i will elaborate more on below.
3rd, the lower front and rear bushings of the Evo arms are different from the ones on the CEs and older. This is the part IMHO that contributes the most to improved handling. Will elaborate more on this in the nxt section below.
But bear in mind though, you cannot quite reuse the brake calipers from the older cars with this knuckle, as the caliper bolt spacing is much wider on 456. So its either you go with OE brembos which forces you to at least use 17 inch wheels, or certain low offset 16"s will fit. From calculations, for 16", 8J +30 offset wheels as a general rule of thumb should fit the brembos but always trial fit first. Or the sliding 2 pot calipers that came with Evo4(same as Evo3 caliper but bigger in size, will fit 16" for sure, may fit some 15" wheels) or the sliding 2 pot caliper from Evo 456 RS. That, will fit 15" wheels for sure. Or the brakes from the car below.
Late model JDM (CE) Mirage Cyborg RS
Direct Bolt On ?
Yes. and no.
Pressed steel arms too.
Unfortunately as with the Evo456 you will need the knuckles for this car too (as the ball joint design for the knuckles is the same as Evo4-5. 6 is different, and not as good clearly, as they reverted back to the "4-5 type" for the Evo 6.5 but fundamentally time saving for Mitsubishi's WRC exploits as it made front axle servicing for the 6 a whole lot faster.)
I should note at this point that using this arm/knuckle combo allows you to retain your steering and tie rod ends. So yeah, lesser hassle.
This arm/knuckle setup will not change your castor angle. But unfortunately also uses the same wider brake caliper bolt spacing as the Evos. It also uses the same 1 pc bearing/hub design but strangely available in both 4x100 and 4x114.3.
Apparently the RS cars that come with a bigger brake option will come with 4x114.3. Otherwise the smaller brake variant has the 4x100. Something like that.
The interesting part about this arm, is that it uses the same rear lower bushing as the Evo4. On the SuperPro website, the Evo456 replacement bushing is the same part number but apparently on my copy of Mitsubishi ASA(electronic parts catalogue) only the Evo4 (CN9A) uses this bush.
ASA does not have a part number for the front lower bushing apparently as it comes with the front lower arm as 1 part so i am unable to know for sure if the front lower bushing is the same as the CE and other cars, or the Evo456. So short of obtaining an arm and measuring the bush for real i am unable to tell you that information.
I have heard of the existence of such an LCA with Evo bushing from one of the local garages i went to some years back. The tech told me that this arm comes with a round bushing in a metal frame of sorts just like an Evo bushing as opposed to the square shaped ones that come with the CE and older cars, and a very significant difference can be felt from it. I thought it was an Evo LCA they were talking about but he insisted it wasnt. Whatever mate. i didnt really bother much abt it at that time.
He was right though. it does exist. If you have to swap out to a front LCA for improved handling, this, my friends, is it. This one from the late model Cyborg RS is the one you are looking for. Evo bushes (at least for the rear).
Rear Trailing arms
All the CE variants from CJ1A to CJ5A share the same trailing arm part number, or most part numbers. The FTO trailing arm has a different part number. The important bit to note, is that all CE Mirages, FTO and Evo3, share the same main trailing arm bush part number. So imho the FTO trailing arm doesn't do squat to better handling. If handling is what you are after. Get wider wheels/tires.
Rear LCA
Apparently there are a few part numbers for CE LCAs. Most are shared with FTO. So no, FTO LCAs are not wider.
Rear LCA bushes
Aha, this is also another interesting part. According to ASA, all CA-CC, CE Mirages, Evo123456 all share the same part numbers for the inner and outer bushings for the rear LCA.
FINALLY.....
To concur. Don't be too caught up on the material strength for LCAs. if there is a difference, between pressed steel and aluminum, you won't feel it; Its more of in the bushes and in your suspension/tire setups than LCA material. Most times these frankenstein LCA swaps and what not is just hurling yourself down a rabbit hole; neverending. So if you want, or must have better front LCAs, get the ones from the JDM late model Mirage Cyborg RS. They are the only ones worth the trouble. With the least drawbacks. Surely Mitsubishi wouldnt make it that way if they are not better?
PS: Mods if this is worthwhile information, pls stickie. and also feel free to correct tech errors if any and also my grammar.