How much time have you got :-)
Engines are different across the 3 models, although engine models are sometimes common between SP/HP (-3BE/BF/BG), and between HP/EP (-3D). SP uses 212 tail rotor driveshafts with driveshaft clamps. HP/EP uses Thomas Couplings on the tailrotor driveshafts. HP/EP have ITT trim for Engine #2, SP has the 212 setup. EP has different Damper Bridges on the Main Rotor Head, but I think this can be retrofitted back to HP/SP. EP cannot fly with older style Damper Bridges though. EP measures rotor torque at the Main Rotor Shaft output to the Main Rotor Head. SP measure at the MGB input from the engines. Structurally, from memory, they are the same. Components are upgraded for each successive model, and engine horsepower increases with each model to hide the fact that the later models are heavier :-)
As far as perfomance goes, you'd have to speak to a driver.
noooby