With 4.5"backspacing (7.5"rim,) and 4.5" lift, I don't think 12.50s would work too well. I'll be putting on TJ flares/cutting, but I think they would rub control arms and inner fender wells etc.
I know BFG makes a 10.50 mud, and have seen 10.50 swampers, and man did they look narrow! So I was looking for an inbetween size of 11.50.
Oh well, I'll probably go w/BFG