When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yes, they will fit fine. Anything wider than a 9 inch wheel will give you rubbing issues in the front at stock ride height. If you plan on lowering the car then things will change. Search the forum and you will find many threads on this subject. Good luck!
It really depends what kind of setup you're gonna do. Do you plan on being pretty low? Do you plan on running meaty tires for performance? I had 18" Work VS-XX's awhile ago that were pretty aggressive, but it was still okay to drive because I was running a 40 series sidewall on the tires rather than 35 (35 profile is more common on 19s than 18s). Mind you I was running stretched tires.
Here's an old pic:
If you're gonna go kinda low then all you really need to worry about is the offset of the wheel. Mine were too aggressive and I wanted 19s, which is why I sold these.
18 inch wheels should fit just fine. It's mainly offset, width, and tire size that affect fitment. Having rolled/shaved fenders and your ride height also determine the wheels you can fit if you're looking for an aggressive setup.
Price depends on the wheel brand. You can get a nice set of Rotas or XXR's brand new for under $800. XXR's are great wheels for the price if you're on a budget. Also, OEM 18 inch wheels from cars like the Nissan 350z, Infiniti G35, and Lexus IS350 are really popular as well and are pretty cheap. They're guaranteed to fit without any fender modifications.
If you've got the money there is a lot of higher end brands like Work, SSR, BBS, Volk, CCW, and HRE that allow you to make custom wheels with custom widths, colors, and even offsets. They can be extremely expensive due to them being 2 piece or 3 piece forged or low pressure cast wheels.