325/70R16 is what converts over to roughly equivalent to a 33x12.50x16 wheel.
Just google Tire Size Calculator and found this.
Now as for a tires... I'm guessing your talking about Interco tires. And by Mud Terrains I'll assume your talking about the Boggers.
The obvious answer to your questions is that the SSR (Super Swamper Radial) will be much better on the road then any Bogger ever will. It's a Radial... it's supposed to. If you have to go with an Interco tire even though you don't offroad you will want to go with either the SSR or the TSL/Radial.
If your not absolutely stuck on Interco tires, you can probably get some different MT's and have plenty of luck. My Kumho's have probably around 30k on them and still probably have another 15-20k if I really push them in terms of mileage. The Kumho SL-71's look pretty aggresive while still looking to have pretty good road manners. l2en would know best (he's a member here who runs them). BFGoodrich makes some good MTs as well, however, I can't vouch for how they work on the road as I've never had them. Lots of guys do though so just ask around if your curious.
I would ask why your getting any sort of Mud Tire if you aren't going to off-road, but I don't have much room to talk there as I do like the looks of trucks with MT's much better as well.