Edit: Do only hitec male connectors work with the Axon II?
From the datasheet it looks like that Axon will accept any standard servo type connector with power in the middle, ground on one side and signal on the other.
I generally find Sparkfun a bit pricey, but any three pin housing with good crimp pins and .1 inch spacing should be fine. Futuba, JR, Hitec, Molex, whatever.
I say "good crimp pins" because I've gotten some bulk pins in the past that didn't grip the pins on the board well, and the connector kept coming loose. I never had that problem with the JR, Moles or Hitec connectors though.