This is the minimum ride height that I could imagine running. Clearance starts to disappear pretty quickly as it goes lower. Inside clearance looks to be about 1/2", outside clearance about 3/8". Front and rear are the tightest here as well, with 3/4" in front and 1/2" at the rear.
The picture below shows the tire at approximately the ride height I would expect to use. The inside clearance here is still about 1/2", all other clearances improve substantially.
I think the body mount itself is fine, but I may have to do a little work on the lower inside corner of the inner wheel well.
As the body comes up further all clearances except the inside improve. The inside drops to 3/8" in some cases. Overall I think I like the wheel and tire exactly where it is, I don't think I'll use a spacer. If I do try one it'll be the thinnest one I can find.
And finally, here's the rear anti-roll bar that I just got. This should take care of that issue once and for all.