I just ordered 215/40/17s. 45s'll give your rims a li'l more protection, but 40's a li'l closer to stock diameter. 225/45/17 is pretty much dead on to stock, but... there aren't as many to chose from in that size and you'll probably pay a bit more.
225/40/17 is dead on stock not 225/45/17.. the only company i know that makes that is nitto and its the 555 extreme. go to www.discounttiredirect.com to find it. tire rack doesnt have it. im going to get 17's later on and im going to get the 225/40/17 since it is the closest you can get to stock and the mph wont be off or anything