I asked Van's about this a while back. They stated there will be no fixed pitch option for the RV-14a, with only this explanation: "the wide speed range argues for a constant speed prop."
The issue may be that the RV-14A is so overpowered compared to most spam cans one can think of, that one has to consider the possibility with fixed pitch prop of trouble slowing down on approach even with the throttle at idle.
I reluctantly concluded that, for me anyway, building what Van's designed is probably the preferable, albeit expensive, way to go, should I win the lottery.
-Paragon
Cincinnati, OH