RE: Walkera Transmitters with other RX does work.
GTX SlotCar
Hitec Eclipse 7 with spectra module is a great radio, I use one for couple years and served me well for the fixed wing planes.
The minor draw back is: 1, the supplied Nicd pack is 600maH, only last for about 80min, it is easy to upgrade with a higher capacity pack. 2, only 7 model memory and there's no upgrade available. 3, For ccpm, only support 120 & 180 swash but you can manually program the mix for the 90 swash.