RE: Suggestions wanted... Mid-size bipe.
The GP ultimate 40 is the perfect plane for your engine. I had one that had a saito 72 on it. I flew it about 200 times and then ended up selling it. It was a sweet flying plane with this size 4 stroke engine on it. I have since moved up to giant scale planes and am flying a 62 inch ultimate. I wish someone would make an ARF ultimate for a 91 size 4 stroke engine. I would buy one in a heart beat. The goldberg will fly on a 91 but it really needs a 120 size engine. Try the GP kit you won't be dissapointed.
Rick