1) Some are available from car yards ect... i've been looking for some m tech 1 for about a year and a half now, and am still looking so this option is hit or miss.
www.carshine.com.au has a vast number of kits for the E30 but they are quite expensive.
2) There are the OEM kits and aftermarket kits, carshine has a few.
3) I went to a bodykit guy today and he quoted me $1100 for a full kit, side skirts, front/rear spoiler and rear apron. That price is not painted, and the kit to me looked very nice. Probably could get it for $900 or so if you really tried.
4) The tail lights can be spray painted yourself, using model see through paint think it is candy apple red. They can also be bought from various places including ebay and
http://www.bavauto.com possibly here.
6) nope lol im looking for the same stuff
Andy.