I believe gyros are a good way to learn to torque roll. Kind of like training wheels. Start with high gain, then reduce it as you learn until you have the gain down to zero, then take them out.
I also believe ths is a great use for simulators though. You can learn the inputs needed really well flying a sim.

As far as the better gyro to use, honstly I'm not up tp speed. When I played with gyros, the JR 900 was the best choic, but it isnt available any more. BTW. you want a simple rate gyro, which just dampens. You dont want a heading lock gyro.

The Expert EX-100 Aero-Gyro (EXRG100) is a good choice. Just turn it on in t rolls and off when you fly our. The instructions w/ it are pretty complete. I wrote them quite a while ago and covered all the bases of using them.