Although I'm not into 3D, I think the Saito 1.20S is a good choice. I made a very nerdy spread sheet to help me decide which engine to buy. If you include the weight of the plane the Saito 120S beat out: Saito 100, YS91, OS1.20III-P. If you can get it for under $300, it will be a best value too. You should always consider the total weight of airplane AND engine before making a power plant selection. You would never use an .049 or a 80cc just because it had great power/weight. You have to look at the entire airplane system.

If you want to go two stroke, MVVS 91 looks good, Webra 1.20 (which I have in a Sukhoi) would be a monster, and a Moki 1.35 would be insane.

gliding characteristics of a cinder block? I thought it was more like an empty shoe box. Ha Ha Ha
That's what's so cool about bipes. The whole airplane is an air brake.