BMatthews

I have to agree that this has come around full circle and you're basically asking us to design the model and systems for you. It's also way beyond the scope of the glider section so I have moved it over here to the UAV forum.

Best of luck with the project but it seems like you have a lot to learn before you even figure out the basics for such a project. I'd suggest you back off and start with a more simple goal or perhaps only study one phase of the project like the stability and guidance system for such a project.

If you're set on doing the whole airplane and you want to make it electric then search for some of the electric model performance calculators that describe how much power you need to fly in various modes. At a start you'll need that to pick your payload and then work up from there. There's a lot of experience and aerodynamics knowledge needed for such an undertaking if this is all new to you. It's just not something you can ask for on forums like this since it would require us to type a book for you.

Instead of complicating the project with long range and distance why not stick with a simple takeoff, out and back scenario that can be handled with only about 5 minutes of flying time. The challenges are the same for the model and guidance systems but you avoid the whole duration thing. If I know by teachers I know that they appreciate a really good job on a simpler goal than a poor sketchy job on a really big goal that can't be adequitely supported in a short frame of time. The KISS principle will aid you. Go for a really deep and well supported effort on only one or two aspects rather than complicating the issue with the full meal deal.