[Igovert500]

Whoaa doubletap chill out, no need to be aggresive...and you put exhaust manifold and a downpipe on turbo cars...not just the exhaust manifold. Headers=downpipe(essentially) it just comes down to different terminology on the application...turbo or n/a

cole...my suggestion...don't spend 2-3k on a big brake conversion...unless you are planning on braking from 100+mph to zero quite often it isn't worth it. Get some decent pads(you mentioned racing pads, make sure the ones you get are good in everyday driving conditions as well...many racing pads need to reach a certain temp before they work ideally, that temp might not be reached in everyday driving applications and you might actually lose braking ability rather than gain), perhaps cross-drilled or slotted rotors, but a whole kit definantly isn't necessary unless you are going to be doing the rough braking mentioned above quite often. Save the money and get a turbo, throw on a 3inch exhaust to let the turbo breathe. Get a testpipe to replace the cat, a downpipe, and intake, maybe even a larger MAF or intake manifold(I'm not sure what is available for the aftermarket Tib). Then if you get greedy for more hp, an air/fuel controller, lightened flywheel, larger injectors, and a better fuel pump will help.
PS. I don't know where you came up with 390plus hp, but realistically a turbo and the mods you mentioned above aren't putting you anywhere near that.
The springs will definantly reduce body roll on corners and improve your handling, so that is a good idea if you are giving it more power.

Just my .02 hope it helps.