Does the 2003 se-r spec v an the 2004 se-r spec v take the same upgrades, or do i need to wait till they make a 00-04 version of the product im looking at...im looking for hotshot header, aem cai, nismo cam, greddy evo exhaust or hks exhsut....anything else i should do?

I don't believe hks makes an exhaust for the se-r, only for the se. Anyway, yes all suspension mods are interchangable between all of the b15's (00-04) and all engine mods are interchangable between any models with the same engine (02 se-r engine parts will fit an 04 spec, etc). The only thing that isn't interchangable are the body mods, things from 00-03 will not fit the 04.

so like i can put aem cai, and greddy evo exhaust even tho my engine is a qr25de..and the thigns i have to wait for are 04 body kits an 04 taillights and o4 hood...but i can also do nething to the engine i want that says 00-03 and anything to the suspension....all engine performance is the same?

as long as it's for your engine you'll be fine