Google does an ok job in some cases for places that sell discount parts...

www.hondata.com offers an ECU reflash depending on year and ECU code.
http://www.hondata.com/tuning_the_tsx.html (a nice link) not sure where you'd find a Toda header easily...

www.ingalls.com has a fairly good rear camber kit, one of the few with toe adjustments as well.

Koni has a set of dampers out now, and both H&R and Eibach have spring kits at this point.

There are 2-3 makers of DOT approved SS brakelines at this point as well, Goodridge is one, my buddy has a set from Stillen I believe.

Stoptech has multi-piston caliper sets, but you'll need a set of rims to clear them. I know BBS has a set that will fit, it might be in the RK or RX line? I've even seen a set of Brembo's fitted from an Accord kit.

I'm quite partial to the www.Redlinetuning.com had hood strut kits available, the prop stick really gets in the way when you work under the hood, they're simply a brilliant fix for one of the cars few short comings IMO.

There are vendors for lots of TSX bits of kit, what bits in specific?

I'll stop razzing you on now...