A good hovering ARF for a 40 bushing engine like the OS 40FP would be a Fun Air 40 ARF sold by Chief Aircraft. 3 lbs 13 ounces and hovers at about 3/4 throttle. I use an APC 11-4.5 prop.

The Fun Air 40 takes a little tweaking when you build it but man does it fly nice and it's very strong light aircraft.

Joe

P.S. There is a typo in your subject line: It says ration instead of ratio.