http://www.canadiandriver.com/tools/...c/tirecalc.htm - You can punch in the stock size and make comparisons and it does all the math for you

As for tires any decent shop should be able to order them for you. If not then order them yourself off TireRack and have them put them on. I have BFG Traction T/As on my Integra, they are all-seasons with a 60k warranty and decent in the snow. If you never drive in the snow, don't mind the tires lasting half as long and want something that makes you car handle like its on rails you might want a summer-only tire like a BFG G-Force Sport. Tirerack has reviews you can read to aid in your decision. Good luck