If you are already running Spektrum the 6040 is good.
http://www.spektrumrc.com/Products/D...odID=SPMSS6040
I plan to put the Orion Vortex VDS2-HV 1605 in my 22 2.0
http://www.teamorion.com/vortex-digi...ervo-en-2.html
I believe high voltage is a reference to being tuned to current lipo 7.4v packs, although there is probably more to that.