I've got a 2003 Galant, 2.4L, and I need suggestions on what you guys have done, what brands have worked for you, what to stay away from, so on so forth... here is my wish list of things I want to do for now:

Lowering springs or coilovers
performance shocks
headers
exhaust
intake, ram air
spark plugs, wires
ignition
computer upgrade
--anything to add power

Go and see what Chrysler Sebring has done, the parts should fit to your 2003 US Galant directly.

springs- Tein (forget coil overs!!!)
shocks- KYB adj.
exaust- flow master
intake- injen
spark plugs n wires- NGK
Even thou i dont have a 8g galant that the brands that i hear good stuff about fro 8g owners. For suspension.......3rd gen eclipse shock n springs will work on club 3g they have them on sale for 350-375 for all 4