forget the 15's just go find a cheap set of 16" 5 spokes with tires on them for like 300, it'll make the car look so much better when it's done.
you can get a set of rims way cheaper then that i got my 07 GP base wheels for 200 with good tires, post a WTB add on Craigslist and say what your looking for
97 GTP DD, 1952 Ford F-1 Resto Project, 2006 Mustang GT "UnDeR CoNsTrUcTiOn", 02 GPGT SOLD!, 98 GTP Parted/Scraped