David
Don't know if you have had any luck with the Schreiner L39 but I had one of these about 15 years ago. It seemed almost identical to the Savex version. Another route might be the Blackhorse L39 which is ply / balsa construction and several people have converted it to turbine using Wren 44's / K45 / P60 dry weight seems to be around 11 lbs. It is a bit bigger than the Savex, around the size of the small Airworld version I think. There is a good build thread on RC groups large EDF jets page 3.
Regards
John