if you get all three motor mounts you wont really need a torque dampner. the motor mounts do a really good job of keeping your engine from moving. the only thing the torque dampner is going to do is give you more vibes in the cockpit.
Not sure what you're looking to use the slicks for, but I AutoX with slicks (BFG R1) and only have the rear dog bone motor mount. Haven't had any issues and the extra grip is worth the price.
