An A-10 might work.  Stunting needs to move lots of air to compensate for drag when you make the turns.  It would need relatively large diameter fans.  Using a small, high speed jet is similar to using a F2D 15 at 30,000 rpm on a Nobler.  It will fly, but the small diameter prop doesn't fly the plane very well.  Level flight and big loops would be OK, but and hard turns would slow it down a lot.

My original idea was something along the line of a scaled down L.A. heat  maybe 30 in. wingspan

I like the idea and several people have mentioned trying it in the past however, like Phil said, it wouldn't work very well. I for one would love to see someone try and I would really like to see the whip-up in some of the recent NATs Air!!!!  I say go for it.

Mike