Funny that you should be wanting to do this now.  I wanted to create the same "Whisper Craft" awhile back, so here's the thread:

http://www.simviation.com/cgi-bin/yabb/YaBB.cgi?board=airc;action=display;num=10...

Read it; it ought to give you an inkling of how difficult this might be.

Sorry Ender Baron, I had not seen your thread before. I have however come up with a solution to the wing problem but it is not as prisice as I would like (hence this thread).
What I have done is to make the Prop parts visible only when the flaps are down (I would like to do it from position 4 onwards but at the moment I can only get it to work from position 1 onwards) and the static wings when the flaps are up. These are tagged as Lav_Dump_Valve and therefore have keyframe animation. Thier start position is with the wings forward so that when the prop wings disappear, it looks like they came to rest in the right place ready for swinging back. The only drawback is that you have to remember to put the wings forward before appling the flaps or it looks a bit odd when the wings suddenly jump in to prop mode.

There is still a lot to do (cockpit windows to cut out, gear bays to box in, textures to apply etc.). Here are some pictures of how it looks at the moment.







All the best
Colin