Probably most stunt airplanes have the elevator above the wing. But some are all in line, others with stab below wing. I've seen some discussion, but all can be made to perform well. I generally put the tail higher than the wing because it is easier to line up the controls that way. One thing is that I want the vertical CG at the same level as the leadouts. The landing gear dangles down below, so I tend to put the thrust line on an inverted engine a little above the wing center line and the tail as above as looks good and lines up the controls.

On free flight models there is concern about keeping the tail out of the wing's downwash, but on a stunt airplane the down wash goes both ways with upright and inverted flight.