15's are cool, but if you really want light rotational mass for drag racing, slap on some HX rims (11.75 pounds
a piece) with some 205/55-14's.
If you want 15" rims, get them as light as possible. Some obvious ones are the Volk Racing TE37's, Racing Hart CP-035's (they come in 15", right?), BBS RK's, Kosei K1's. For a stock look, the '96 GSR rims (the ugly ones with the big center cap that says "Acura") are the lightest by a little bit. Check out
http://www.wheelweights.net for more rim weights.