??? on wheel spacing

I am planning on installing a 4.5" lift on a '90 xj. I want the large cut-out bushwackers, and I want the tires to fill out the entire fender flare. I plan on using 33x12.50 ssr's. What wheel spacing should I be looking for? I don't want the flares to look too wide for the tire.

I have an RE 4.5" lift running 32" MT/R's. The backspacing is 3.5" on black rockcrawler wheels. I had to cut a little back on the factory fender flares (front only) and some sheet metal underneath. It doesn't look too different, but eliminated all the rubbing in the front. Rear has plenty of room.

My dilema is that I want the wheels and tires to be wide enough to fill out the fender flare, but not go so far as to cause me problems. (bearings, etc) If I go with a 3.5" or 3.25" backspacing, am I asking for any trouble? I think this will give the truck a nice wide stance with 33x12.50 tires.

If I remember, the bushwacker flares are 6" wide. If so, I'd go with the 3.5" backspacing. That'll minimize rubbing and fill the flare. If they're more narrow than 6" flares, you probably want to spend some time and measure exactly how wide the wheel will be. Remember that you're only considering a .25" difference in backspacing which isn't really significant from an appearance perspective. I clear the fronts on turns fine with the 3.5" backspacing on 32x11.5" tires. the stance is nice and wide but not overly wide. Your best bet is to spend the 45 minutes and measure exactly how far out you want the tires to be and buy your wheels based on that. I've learned that the trial and error method costs too much to get it the way you want.