That is a great tire for mud, and I feel like a narrower rim is better, like the 15x10 in most cases with a 14'50-wide tire 35" and up. A taller, skinnier tire will dig deeper to get more traction. But with a 33x14.50, I would go with the 15x12 rim just to get a better "footprint" or tire contact with less chance of popping a bead if your air down. The wider rim will have less sidewall buldge to help the grip, but less exposure to punctures. You will have a bit more weight from the wider rims, too. I'm looking at a set of 35x14.50 Boggers on 15x10 rims for strictly mud. There's more info on rim width if you search the forums.
