Charles this is an interesting idea but I believe this kind of belongs in the stunt design forum rather than the electric.
I would put the design on a piece of paper or a napkin (all great ideas start on a napkin) and post it so we can get an idea as of the general looks of the model.

Engine behind the fuel tank is not a practical for stunt because of the 4-2-4 and the way it works. In this type of model with engine in rear tank in front if you put the nose up the fuel drops in to the motor and runs 4, and opposite for nose down (fuel runs from the motor and the motor leans and goes 2 in a dive). This is the same like saying motor slows when you climb and speeds up when you dive. Conclusion is that the only way to get good motor run is with electric and active timer. Also active timer and servo actuated throttle on and IC would also work.
Also with electric you can put the battery just about anywhere you want to have it be to balance the model so you open the door to about any type of wing stab setup you want to have (I am thinking forward sweep on both to facilitate pitch sensitivity).
And here is an idea make a 1/2A Electric model out of flat balsa and test whatever idea you think will work and once you zero on a good platform elaborate on a larger model. Get something to fly first then try a forward swept horizontal then a straight on the a swept back one and see which one works best. Then do same for the wing, sweep it back forward leave it straight and then play with combinations of both. Heck make a second wing and try the biplane idea while you are at it.

One of the things to consider is the elimination of the prop wash. This high velocity air from the prop that hits the horizontal stab at high velocity greatly increase the efficiency of the stab. Without it you need to make up for the loss in other ways (could get away with it but you have to push that CG back to the max to max the pitch sensitivity).

Good luck.