15x8 or 15x7 4.5" backspace and you will be good to go. Personally I would go 15x8. I don't know if you have your rear wheels yet, if you don't go with a 4" backspace and your front wheels wont stick out further than the rears. As I said before, I had 15x8 4" backspace all the way around, with about 1 3/4" drop in ride height in the front and the outside edge of the tire hit the upper most part of the fender lip when you hit a large bump, but they barely hit. The additional 1/2" of backspacing would have cured this problem, as well as looked better because the fronts were noticeably sticking out further than the rears. If you have lowered the car and have a decent sized tire, the tire may rub the sway bar on the front edge of the tire and the inner fender on the backside of the tire at full lock. It is not that serious though and a XH steering box with 16" wheel stops would fix that problem if it bothers you. The 15x7 might also cure that problem, but it will leave you with a little less tire width options.
