Vincent,
Hmmm, need to do a bit of research but saw these and liked the look of them...
http://www.servocity.com/html/hs-85m...hty_micro.html
whilst I'd never put a Hitec servo in one of my jets I thought these would be fine for a gear door?
Rgds,
Mark
PS Just noticed that a certain World Jet Master used servo actuated gear doors on his Hawk