Stock tire size on the 17s are 275/40 and if you go to 18s you have to go 275/35 to keep the speedo accurate. Just gotta lose some sidewall and you're fine.
Josh, I'll shoot you an email when I get home (at school right now) but here is what I'm thinking. I'm selling with wheesl but I'm also selling them with tires to make up for the money I won't get for the wheels. Tires are brand new with just under 5,000 miles on them and I haven't been hard on them at all (read: massive burnouts, drag racing, autox, these tires are fresh). Kumho Ecsta Supra 712s 245/50/16. I know of one wheel at least that the place I took them too happened to scratch up. I need to inspect the other wheels further. So since the wheels have 72k miles on them and the tires have less than 5k on them, I'm asking around $125 for each wheel w/ tire, so around $500 for the whole set plus shipping costs. That will get me tires for the new wheels and then i just gotta come up with the money for the new wheels. Anyway, let me know if you still want them after all that. That $500 is the "friend price" and I can't really go lower without shooting myself in the foot. I'm asking $600 elsewhere for everything.