Welcome to this very addictive hobby.

This question is asked a few gazillion times, but, Ill give my point of view.

The Hannibalito series of feathers use for drive the common Graupner Speed 900BB torque motor. With a mod1 Z12 gear on the motor, and a gearratio 4.5 to 1 (Z54 on the wheel). The wheels are custom made, and have different diameters, but were prefering around 80mm diameter.

Batteries, NiMH 10 cell stickpack with Sanyo 3600mAh or the GP 3700mAh . We also have a 4 cell A123 pack, but those arent approved yet for the use in feathers by the organisation.

Speedo, we used the expensive overkill speedo the Sidewinder.(we also use that in the heavies). But now the Scorpion XXL is taking that role.

But the easy way out, for acceptable money is to use batterydrill motors and gearboxs. A lot of succesfull machines use this.