Autocross/Track Duster Wheel Help

Thanks for all the info guys. I am more focused on the rim size and knew 315 was way more than I need or wanted. Just seems that article drove the thread that way. I tried a 17X10 rim with 275/40 my buddy had laying around. The inside of the rim rubbed the tinniest bit on the top of the upper control arm. I feel I need to go up to a 18 to make sure it doesn't rub on the upper arm. The rim we tried had 15mm offset and we put a half inch spacer up front. I believe that puts us at a 24 or 25mm offset. The rims we tried fit in the back with room to spare. Up front it looks like it should clear with some minal rolling of the upper fender lip. I am just trying to figure out all I can before ordering a combo that doesn't fit. I know the safe bet is just to get a staggered set and drop the front to 18x9. However, for track and autocross I would ideally want it the same all around.