so i finally figured out thanks to everyones help that im gonna get the 17"s and its comming with P205/40zR17 now my final question is are these rims and tires gonna throw off my speedometer?
Yes, your speedo will register 2mph faster than actual.
Using those low-profile tires will not significantly effect your speedometer. http://www.carid.com/subaru-impreza-wheels/
You can compare tire sizes on this site - http://www.miata.net/garage/tirecalc.html
the difference between your stock tires and the ones you want to get should not be big enough to effect it much if any.
Looking for a Used Impreza in your area?
CarGurus has 16,071 nationwide Impreza listings starting at $1,995.
Search Subaru Impreza Questions
Subaru Impreza Experts