RC receiver to DC Motor servo controller board?

Is there a ready-made position servo controller board which can be controlled using an RC receiver output? (Think of substituting a BIG servo DC gearmotor for a typical RC model servo).

Ideally, it would work with a 12V 6A reversible DC gearmotor on the back-end. The commanded position information would come from the pulse train out of the RC receiver. Position feedback of the servo shaft from pot or optical encoder?

Not sure if this would be the cheapest option, but it is an option:

Pololu - Pololu Jrk 12v12 USB Motor Controller with Feedback

I should note, though, that large DC motor drive H-bridges (which is what this is, basically, plus the RC interfacing and such) typically are expensive to begin with; also, for this driver, given the h-bridge (I think) it is using, you may need to add a heatsink to it (basically bonding the heatsink using thermal-conductive epoxy to that largish IC you see on the board).

Another option might be to hack a standard R/C servo to control your larger homebrew servo (which may or may not be easy, depending on the servo involved, and its control board).

Thank you, that is just what the doctor ordered...