http://ranglebox.com/

If you want some high power, pre built stuff then you can order from here. They do Motors which are bigger than Drills with a prebuilt gearbox and also ESCs which again should be more than what youll ever need in a feather.

Just an alternative should you decide you want to buy something which can then be reused into a more combat focused machine afterwards - many championship robots do still run on drills however, so its not urgent to buy anything above whats considered starter (just worth being aware of)