The things that we found important are speed (RPM). compression and reducing friction. Granted, our shooter is not curved, but it does rely on the same basic principals as yours.
Good luck
Edit: after some digging here are some specs.
We use a 6" performance wheel directly driven by a CIM. Any faster and we found that we didn't have enough torque.
The compression on the frisbee is about a half inch (the plastic actually deforms). The trick here is to find a point where you get the proper surface contact with the disk while not stalling your motor.
Reducing friction is the tricky one. You want the disk to travel through your shooter with as little resistance as possible while still imparting spin. We just used plywood with a nice finish.