Ash,
if you end up streamed 'sensor op' wet or dry, you will almost certainly end up on the MRA4 at RAF Kinloss. I believe though, you won't be streamed until you're already in training. Therefore you could be streamed loadmaster and end up on fixed wing aircraft at Brize Norton, or if you get streamed rotary you will end up on helicopters at Odiham or Benson. Doesn't matter where you're posted on rotary because you'll spend most of your time in the desert!
My info' may be slighly out of date though, it's been a LONG, LONG time since I went through flying training! Either way best of luck.
Dicky