That's how i fly my E5 super stretch. Use a Scorpion HKIV 4035-560 motor with a 14T pinion and a Tribunnes 200A esc. Not that it needs 200A. It's just what i had and fits nicely. I fly on both 7s and 12s depending on my mood.
As far as the parts needed to stretch i installed a 54T /11T tail drive combo from a E7SE or N7. Both use the same gears. The tail is just the boom, torque tube, boom supports and tail control pushrod from a E7se/N7. You could fit a E7/N7 rotor head but flying low head speeds like i do the E5 rotor head works fine. I run 696 mains and 106 tails.
320-111H
320-154
315-120 boom
320-500 torque tube
315-117 boom support
315-111 tail push rod
You will also need TT bearings and ends for the TT. Ends for the boom supports, and pushrod.
I fitted a E7 canopy to mine, just to see what it looked like.
chuck