I bought a WOT 4 Mk2 ARTF model, but decided that I prefer Electric. Being comfortable with SketchUP and owning a Laser cutter, I decided to do some careful measuring and reworking...
I used conversion information from http://www.chrisfoss.co.uk/ and the excellent propCalc here: http://www.ecalc.ch/motorcalc.htm.
This page documents the various stages I went through.
A kit of parts can be purchased here.