Right now i have a 6 in lift, and im looking at buying some new tires. I will be trimming my fenders some as well. What tire will work better at both rocks, and mud. I do quite a bit of both. Also, what would be a better size? 36/12.5, 36/14.5 or 37/12.5? One more thing, how any miles could i expect to get out of either tire?