If you just stick to Track, i'd say the 912T or the 916AT are great options if you really need something stronger than your 811 c/t. The 916AT would be a little stronger on the backend, where the 912T would be smoother and probably more of what you are looking for from the sounds of things.
A - Angular, most skid, most backend reaction
C - Continuous/Control? a little smoother on the back, less skid/flip
T - Traction, strongest covers, smoother reaction overall