not that hard to find ae86 performance parts, Whiteline makes great adjustable large diameter sway bar kits for them for both front and rear. there are numerous companies that make engine and exhause products from exedy stage 3 clutches to , PDM-Racing.com has a decent selection of basic upgrade options from KVR cross drilled rotors to cold chilled billet-cast racing cams, as well as alot of Whiteline suspension products specifically for the 86. im not gonna make a list for you, go check them out here:
http://www.pdm-racing.com/products/t...r.html#corolla
mind you this stuff isn't cheap, but i does work, these are serious performance parts
like REN69 said, check out
http://www.dorikaze.com/, they specialize in the ae86 over there, and most likely they're will be someone selling what you want/need.