You use a +35 in the rear (they come with a huge lip) and the rear fits perfect after the fender lip is ground down (on cars lowered a decent amount below stock). A +20 is used in the front and they sit about 3/4-1" away from the caliper. A +28 or possibly a +30 would be optimal in the front, but they don't make it. A +20 fits fine, but if you like a slammed ride they will rub the plastic inner fenders on the outside (side closer to fender edge). A +28 would bring them closer to the to the caliper and therefore bring it in towards the inner fender causing it to clear the edge of the inner plastic fender (the lowest point).
The +20 and +35 is the only available combo you can use with no spacers.
If you want perfect fit, buy a spacer and longer (arp) wheel studs for the front and go with the available +35 (brings the wheel closer). An 8-10mm or so spacer will bring them back out to clear the caliper while still keeping it close. Remember the higher the offset the closer the wheel.
When I say "perfect fit", I mean having your car slammed with no rubbing. These wheels look awesome for the money, and especially when you paint them black (shown above). My friend had coilovers on his supra, so we raised the coilovers from being bottomed out and the car tucking (tein basic)..back up about 7 threads all the way around. It still has a mean stance either way.
He runs a 245/40/18 in the front (should have went 35 series I think), and a 285/35/18 in the rear. You could go with a 295 in the rear and it would not buldge, but we didn't grind his inner lip yet.