Kress RK 740 / OS 25 DF - EDF equivalent?
 

I am about to build a Horten 229, I like nitro engines, but not want to mess with ducted fans, so I'd like to install EDFs.
What size should I get? This has about 81" wingspan, not sure about the weight. Balsa / Ply construction.

It doesn't have to be crazy fast, but not slow either :-)

Thanks