Okay,
The BFG's (AT or MT) are listed as a 325/60, but they are basically a 31x12.50. For whatever reason, the fine folks at Goodrich just used P-metric sizing. 31x11.50's are out there, just look around. Goodyear made, and still might make, the old Wrangler MT (not MT-R) and AT in that size. There are 31 inch Swampers in 10.50, 12.50's and 13.50 widths. M/T 31's in various tread designs from 10.50 to 15.50.
Don't bother to try to put a 31x12.50 on an eight inch rim. It is far too narrow. Use at least a 9 incher, a 10 incher is even better.
I have a rather crappy tire shop job at Sam's that does little more than anger me most of the time. The store has a few qualities, but is managed be a fleet of assholes. The only true benifit, other than pay, seems to be a fair understanding of all this nonsense. Let me know if you have any other techinical questions.
How it looks should not matter if you plan on needing the extra with for performance reasons, but that is just my opinion. This is coming from someone who allows and even encourages his girlfriend to drive into trees, however. The rusted-up pipe bumper is there to knock them down, not sparkle and shine.
Brian