if you are going for stance, then i definately reccommend coilovers.
if you are going for control in your suspension when turning etc, then coilovers are once again much better than springs,
also i would be getting a rear sway bar, along with front and rear strut braces. our sponsor henry can supply all of those products being great quality, for an affordable price.
just fyi, coilvers are not legal. very hard to get defected unless you are going for a blue slip, and cops dont really know the difference, nor do they look that deep into your car if you ever get RBT'd, just know there is a chance.
they can also void insurance claims, depending on the incident, but once again it is unlikely for them to be the cause.
look forward to see how your build goes.