One of the reasons I got away from 1/10 scale buggies was, because large knobby off-road tire selection is very bad. I gave up searching for tires. If I were "bashing" a buggy around, I'd have a set of tires for both off-road, and on-road RC fun. HSP, Exceed, Redcat Racing, DHK 1/10 scale buggy tires are what I would use for off-road. I'd try and find them unmounted if possible, 'cause I'm not sure of front offset you would need.
06025 rears06009 fronts