I personally would do solid motor mnts and rubber trans mount. urethane should be fine on the tranny. im assuming this is more track than street? solid motor mnts will keep the engine from twisting. you don't want any deflection!
I do have their torque strap getting shipped as we speak , that should take a bit of the twist out ??? I really wanted to stay away from solid mounts but if you guys think that's best than I'm up for it, if I don't want to go solid will polyurethane mounts from Schumacher be the strongest type . 19Dart66. That is a DR-4-4