I picked one up a few weeks ago. I've been trying to decide what engine to put in it. I've got an OS 25F ABC and a Saito FA-45. Both are older engines. I think I've decided to use the OS since it is smaller, lighter, and more powerful. I also found I would have to hack away some of the engine mounting area to accomidate the carb on the Saito.

I've done a bunch of searches and did come across someone who said he flew one with an OS 25FSR, which is a less powerful engine than the ABC. He said it flew fine. From the specs on your engine, it should do well. Don't know what to suggest on the prop size.