I was flying my GP Soucy extra with an super tigre G-2300 and it was very good. You will find when you try to install a gas engine in this plane that the airframe is a little too small (I tried it). Any engine in the 50cc range is going to be too heavy and too big and have way more power than you will ever need. You will also have prop clearance problems. You will have to add weight to the tail to get it to balance and the plane will weigh in the 14 to 15 pound range when you are done. It will fly at this weight but the wing loading will be high. Also smaller gas engines power to weight ratio are not very good. I tried my 3W-24 in the soucy and while it flew the plane it was not as fun as the large glow engine. If I was starting out in gas powered planes again I would go with a 50cc size plane and engine. You will be better off in the long run and have a better flying plane.

Rick