36 will be fine, build the plane light, after that you just need power to lug the bigger engne around.
seams theres two ways to hover, constant throttle, like post above and you learnt that planes hover point, or throw it about and just play with throttle, like i do, i actully cut back to idle sometimes and blip it all the way up when i hang. seams to impress the guys more lol

dosnt the Wasp have glassed bits in it?? like a center sandwich or sommit... sure i read that somewhere, probably wrong. i guess if it does, you need these if you go for 40 and upwards engines.

i think you should go simple and strong. the Correx PBF is both and cheap, theres one here, but i cant get it to hang propperly, the Dust Unlimited and Lill Rippy both fit the bill if you add rudders, tho not having a Fuz, they like to sway alot. but are more than strong enough and light as hell.
the Magic hangs well, is pre built and cheap.
Wasp, was designed for hanging and also does lots of other weird stuff.
sudden comprimise comes to mind...... build a Wasp with a GF LE and one running down the fuz too. also for rudder post and tailplane, this will give all the strenght you need and keep it light as well