So I've decided on some 17X7, 40 offset rims and am wondering which tire you guys think would be best?

225/45/17 will match up best to the stock tire size.

Yup, I'd go with 225/45/17 if I were you, even though I've seen 215/45/17 on a JDM TRD flavored new iST.

205/50R17 is the recommended size in a 17", but you can get away with running a 225/45R17 to keep the tire close to the stock overall diameter. I would use 215/45R17 if I wanted to increse the gearing response a bit more, but it will read my speedometer very inaccurately.

Why don’t you check wheelsnext.com its great online source for tires and rims .I had a wonderful experience I wanted silver wheels. While making an online search –a long time search and reading some forums and finally I stumbled upon wheelnext.com and my search ended there. The exact wheels and tire I was looking for was right there. And it was not just my choice of wheels that was met on wheelsnext.com, even the price range was reasonable. I made my pick in not more than 5 minutes..

Thanks for the help guys, my new wheels are in the mail and I'll post pics when they arrive!!! I decided on 225/45/17.

Finally got em on. Thanks for the recomendations.
http://i47.photobucket.com/albums/f194/killeatandrepeat/IMAG0130BETTER.jpg

http://i47.photobucket.com/albums/f194/killeatandrepeat/IMAG0128BETTERFRONT2.jpg