I agree on the stock wheel. Dont go with those spec v wheel because they bend or crack. The stock 16inch wheels hold up pretty well and won't slow you down like a larger wheel.
Seems you got a good deal. 83k is nothing milage wise. I have 267k on my SE. All I've done mod wise is KYB gr2 struts for a 2004 spec-v and a header. The header was definitely worth it and gave a decent bump in power and mpg's. This is my daily so I'm try not to do much. Becareful as these cars rust pretty quick.
For more info check out my thread
http://www.sr20-forum.com/members-rides/25706-back-b15-game.html