Very difficult to find 19.5" rims in the new GM bolt pattern of 8x180. I only found two, a Vision 81A and a Rickman steel wheel. The steel Rickmans sell at a ridiculously high price. The Vision rims are a better wheel at a better price.
The 19.5" tread patterns are all highway designs and not A/T. Good for high mileage. If you really need 4800 lbs. at each wheel the expensive may be worthwhile. I looked at the cost and opted to use my factory forged aluminum rims with Nitto 285/70R/17 tires rated at 3750 lbs. instead. The upgrade cost me less than $500 out of pocket and the purchase included free rotation and balancing for the life of the tires.