RE: Nosen citabria engine
Years ago we had a fella in our club who flew one of these on a Supertigre 75, and it flew the plane around alright, just not much reserve power. I think we all tend to overpower our airplanes( me included) but sometimes it is refreshing to fly one powered somewhat scalelike, and fly it on the wing. I think something in the 30 cc class will provide ample power to fly this airplane fine for you. Mind you it's not going to fly like a Pitts, but then the real one doesn't either. The Citabria/ Decathlon is an Aerobatic trainer( Hence the name Citabria is Airbatic spelled backwards), and should fly somewhat like a cub or maybe a clipped wing cub on a mild dose of steroids.
Just my .02
Bryan