I think a ducted fan engine would be a horrible choice for a classic pattern plane. This is just my opinion of course. The DF engines make their power at 20 - 23K, with no regard to midrange throttle, and are designed to idle at 6k or so. I run an OS91 and Webra 80 fan engine on prop planes and have fun with them, but I don't think a pattern plane would work for them. You need a really clean airframe to let the engine unload, and I don't think a pattern plane would work. I use specifically designed speed planes with very little frontal area and very thin wings designed for speed to let these engines run.

Scott