I think if you haven't been around ducted fans you don't need to skip them. They are a great tool for troubleshooting and have the same flight patterns as any turbine. Ducted Fans can also teach you alot about how the jet flys and gives you a feel for the speed. Understanding everything mechainically and aerodynamicly has alot to do with thing, and with jets be it turbine or ducted fan there are many things that require annual inspection and "tweaking" only thing you are giving your self by starting with turbines is rarly ever having engine problems unlike fans that could quit or break at anytime, more money invested, extra flying time with a qualified pilot. I think as far as arf's go Yellow Aircraft used to (probably still do) produce arf versions of thier .91/Turbine Powered F-16 and F-18. Also JHH Has a .45 sized BaE Hawk Arf but they are hard to come by as I have heard. IMHO you should pick a kit in which you can convert to turbine when you feel ready to and built it yourself so you can know what went into it and understand more of how things work.