Airfix used to do some of those triangular display stands they used to put in their kits, but I am not sure if you can still get hold of them. And to be honest, personally I don't really like those.
You could always make your own base and support the model with clear acrylic rod, that's if you can get some thick enough for it. I am sure you will get some more helpful replies as there have been a few flight displays on here. Try posting in the aircraft section, you should get more responses in there.
I am a Norfolk man and i glory in being so
On the bench: Airfix 1/72nd Harrier GR.3/Fujimi 1/72nd Ju 87D-3