We had a little Air Corps here of GB Cubs - six of them, all built by the same builder, all clipped wings, all with OS 91 Surpass engines. I believe the 70 is a better match, but the 91 will really wake 'em up!

I built one as a camera plane - full length wing, OS 61SF two stroke. Two pound 8MM camcorder in the cabin, looking thru the flat glass windshield I used. Looked like you were sitting in the pilots seat.

An OS 70 (or copy) or Saito 72 would be my choice.