I just started flying my 1/4 scale GeeBee R1 built from Henry Hafke plans It weighs 15#. I tried an OS 120 pumped engine for the first flight. It didn't quite have enough power, but the plane flew after a long takeoff run. I now have a Saito 180 swinging a 16-8 APC prop, and does it perform now. About a 30 foot run, and takes off in a 3 point attitude. I do loops, rolls, 4 point rolls, slow fly, etc.
This plane is not a killer aircraft as everyone has been led to believe. Actually in the air, it's a *****cat. But it does like to nose over on landing. You must slow it way down close to the ground, and kick in a lot of up elevator(I click on high range on my transmitter as I get near the ground). That's the only bad feature of the GeeBee. Slow it down.
Good luck on your GP geeBee. It should fly great.

Bob S