ORIGINAL: ChuckAuger
For small planes like this, I've been using the Futaba 9252. .14 speed and about 91 oz in Quite a ways from 5Kg, but then so are the 811's.
After looking at the 9252 I noticed the 9451. It's same price, more torque, faster, and runs on both 4.8 and 6 volts. It's .2 ounces heavier.