The Pronto has always been one of my favorites. I built one a few years back for electric. I used 1/16" balsa all around. Turned out it was too light/thin/weak. Fuse would torque causing all sorts of flying issues under power One of these days, I'll build a new fuse.
Here's my post from the thread Robert mentioned: http://www.rcgroups.com/forums/showp...1&postcount=60