Don,
I owned and flew a Skymaster F-4 for two seasons and loved it. Mike Lesher still flies one and I think it sleeps next to him at night! Lowell Wexler flies a FEJ F-4 and thinks it's the best there is. Personally, if I went with the FEJ...I'd go twin turbines. It's a BIG bird. I flew my SM with a Jet Central Rhino and it was perfect with a Tam pipe. Pretty stable plane...you would not expect it to be with the wing design but it is a lot of fun to fly. Between the FEJ and SM ARF's...I'd go bigger and get the FEJ...IMO

Best of luck!
Rex