You can stay with the 225 and you should still be ok. I have 215 on my front wheels and they are 9" wide. The 215 is a pretty good stretch, and I've heard 205 is the smallest you can go on a 9" wheel. So you can easily go to a 205, depending on what you want to do. If you want a meaty look go to a 235 or 245. It shouldn't look too bad with a 35 aspect ratio.