You might try a Menace with an OS 32 or TT 36... Great plane with a 9 - 10 oz wing loading.... Really awesome for 3D and FunFly Competition.

As far as compairing the os 32 with the 46... Two very different engines for different planes... I'd say the 32 is good in a fun fly up to 4 lbs and a 46 is good from 3 1/2 - 5 1/2 lbs. I like the 10.5 x 4.5 APC prop on my TT 36 and a 11.5 x 4 APC prop on my 46. When I had a tunned pipe on my 46, a 12.25 x 3.75 prop worked really well...