HI,

I recommend the Excelleron 90 with an OS120.. I fly sportsman and have two excelleron 90s with OS120's it is a perfect match,
the OS120 has all the power and economy, plus the OS120 is an excellent engine to set up.... 1 tank and your off and running.

Cost wise the Excelleron 90 is inexpensive, and the only thing you need to swap out of it the hinges (go with Great plane pin hinges) and
the landing gear to get better clearance for the prop.

it flys excellent, and is easy to maintain.

Pls note I had YS110 in my excelleron 90 but due to idling problems I went with the OS120 and was very happy with it.

Make sure you balance the plane and it will fly anything you want.