Bv,

Your best bet is to ask the guys at the field what engines are popular that way you will have lots of help when it comes time to set it up.

My two favorites in 2s are the Thunder Tiger Pro .46 and the OS line of engines. My TT is going on Six and two of my OS are still going after 15yrs + I bought them used in '89 and only have needed to replace the barings.

BTW I wouldn't be to concerned about using the engine in the trainer for your second plane. You may find that you still want to keep you training in flight ready condition or you might want to go four stroke on your next model. Its very difficult when starting out to be able to predict which power plant model 2 needs because your tastes and flying abilities may change radically after you solo