That is one slick looking concept man! So far as a slow flying edf? Perhaps so long as you keep the wing loading as low as possible but to be honest that thing does not look like it wants to be a slow flyer. When designing a scratchbuild edf I personally start with the motor and fan assembly I want to use first and then purpose build a flying platform around it taking into consideration inlet to nozzle ratio, thrust, auw....so on and so forth....slightly different approach than a prop driven model. There are a few more tid bits I would like to mention but it is way past my afternoon nap time so brain function is a little slowed at the moment but I will be back. Best of luck!