i'm looking for an OEM nissan steering wheel (B14 leather i prefer) so i thought that maybe b15 leather steering wheel could be installed i haven't had one in my hands but they look similar on pics.Arm rest - Gspec
Someone has gotten a Silvia steering wheel to fit on SR20Forum, I believe. Otherwise, there are wheels made to fit our cars. Sparco wheel
Sun visors - eBay is where I got mine.
Lip - Honda Accord lip, Stillen lip, etc.
Side skirts - Post in the wanted section of the classifieds, or search in there. I don't know if there are side skirts for sale right now.