I'd bet you'll find out that 3.5 bs will really limit how wide a tire you can use. 4.5-5 bs would be a much better fit.
I have a couple pairs of 15x8.5 with 3.5 backspace, and I can't get proper sized tires on them for the wheel width, that will fit anything I own. Won't clear the fender.
But I've got 10.5x28 slicks on 15x8.5 centerlines with 4 7/8 bs on my car.