Clint,

I would suggest building with the wing extension that Fix-it proposed. I built one that way and have a schnuerle .10 on it.
The Medallion weighs slightly more than the baffle Fox .15 without muffler, I think...but not enough to worry about.
Forget movable flaps if you are just flying for fun. More trim adjustments that you don't need.
Try an 8x4 prop, 15% fuel, and .012x52' lines. That should get you in the ballpark.

Good luck with it.

George

Edit: Trying to include a pic, if it works. The lower one is stock with a baffle Fox .15 and the upper one is with extended wings and a TT 10.