Just for reference, I found this 80" version here: http://www.jensenjetmodels.com/id25.htm

Although they list a kit, they only offer a short kit with the fiberglass fuse, and other components, you have to buy the plans and build the wing, tail, etc. I think this is the old George Miller design.

Looks like no easy way to do it....

I'm surprised with all the jet manufacturers out there, no one offers an 80-90" kit/ARF

It's perfect for EDF conversion due to the high lift wing, and the fact that it doesn't need to be "fast"