We got Energy Suspension polyurethane mounts. In our case we bought a complete set that included cab mounts, spring bushings, sway bar bushings, and a few other things. It was a very complete kit. I did order more grease for the bushings, there isn't enough in the kit in my opinion. That was my only complaint about it. The cab is very solid and the suspension is squeak free and works nicely on the new bushings. I think it was binding before.
The only other problem we encountered was reusing the steel caps for the body mounts. 4 of the 6 were rusted through. I ordered 6 new ones and through the rubber away. It's not their fault, but be aware they expect you to reuse the steel. The nuts for the cab mounts are captured where you can't access them. They may bust loose when you try to remove the bolts. You'll have to cut holes in the floor or behind the seat if that happens.