I'd stack Drive or RPM with CordygenV02 if you're looking for maximum performance enhancement. And yes, I've done this stack (have Cordygen5 and V02 right now). Good stuff all the way around. If you're looking for power, nothing really beats good old fashioned creatine mono, all things considered. But cre mono added to the two above supps would be just about perfect.
Although it should be pointed out that training for endurance while also increasing speed and power isn't very compatible. Speed and power go hand in hand. Endurance is somehwhat like the opposite of those two things.