for looks if you want to stay away from body kit I'd say yeah S2000 antenna(20 dollars at honda dealership). Tail lights between 65-120 at ebay. wheels of course.. www.wheelguys.com
have good selection and good prices. underbody neons 100 bucks. carbon fiber Hood
(500) you don't need to worry about matching the paint. performance options are pretty basic. exhaust, Intake
, turbo if your rich, nitrous if your brave. if your worried about hydrolock get a SR it's only a difference of a few HP and if you add the breather valve it pretty much kills those HP anyways. THe Injen
one is sexy.
PS custom interiors are awsome. nice floormats painted dash custom gauges head units, seats, short throw shifter for performance and shifter knob for looks. neons