Here is a lot of interesting information about the signal output of a receiver:
http://rcarduino.blogspot.co.uk/2012...iver-with.html
For a featherweight I imagine with the right knowledge you could make a speed controller, it's not too complicated but may well be as expensive as a pair of botbitz controllers. One thing I would say though is don't underestimate the currents involved- it needs to be designed to cope with the stall amps of your motors so depending on motor choice I'd design for 50A per motor to be safe.