I would check around online and see what people report on the 19 Turn and stock motors.
So far, for 19 Turn the best seems to be the Reedy 19T Quad Mag Motor though gearing can be alittle odd as it has SO MUCH TORQUE. The one that I hear is the worst is the Epic motor ironically. People at our track tried these motors, a few runs and they were done. Our X-Ray driver had a few choice words for that motor
I personally like the Quad Mag and the Peak Dynasty.
For stock, you can't go wrong with the P2k2. The MVP when tuned with Big Jim's suggestions puts out great power too, an the magnets on it are a better grade than what trinity uses.