Been doing some looking at this concept in the past few weeks. packaging and arrangement of all the appropriate bits is tough in these small clean designs. This is actually getting to the point that I'm reasonably happy with it. The main gear doors are really just place holders but work in the model. The Nacelle looks like it can fit 650-750cc engines direct drive and up to 48" props. Been looking at a bunch of engine choices and bearing/prop flange ideas and there is a lot of off the shelf stuff out there. There is enough work here to figure out that this could really work well and it is also a good candidate for wing extensions like a competition glider. This would provide more aspect ratio and area to carry more fuel for a long range flight.
Anyway, stuck between consulting projects right now and trying to learn some new stuff in Solidworks so I thought I would share.