I don't know how big you want to go, but if you can find a Bud Nosen trainer kit, get it and build it. It looks like your typical high wing, box fuselage tricycle gear trainer, roughly the shape of a Cessna 172. The wing is held on with 4 nylon bolts, and I think that it was originally designed to fly on a .90 2-stroke, but it is plenty big enough for a gas engine.

I "inherited" one from an older gent in my club who sold me a US-41. He had built it 20-odd years ago and it needed some TLC. I converted it to a taildragger and put the US-41 on it (plane weighs 22 pounds, paint and repairs fattened it up). It flies as easy as any .40 size trainer, although it doesn't float as much, and does very quick rolls in spite of its 96 inch wingspan, nice loops, stall turns, etc. Takes off in about 80 feet and lands and stops in less than that. Mine has strip ailerons, but if I ever have to fix the wing, will make barn doors and add flaps. You can see a pic of it in my gallery.

The other plane I'd highly recommend for gas, and has VERY docile characteristics but is capable of a lot more than appears, is the big Sig Rascal 110 ARF. A G-26 will fly it to the moon. I had a .40 -size once, loved it, and then had an opportunity to fly a 110 at a fly-in. It was as easy to fly as the .40 size, and its owner could hover it, do rolling circles, Harriers, it was surprising what the plane would do.