Howdy from Texas, new member to the EAA here, I've joined up for my passion for aviation but also because I am pursuing the design of an ultralight primary glider.

Now I'm no stranger to conceptual design, I've competed in a couple design competitions before, however, these were all theoretical (I just fleshed out ideas in CAD).

I have chosen to design a primary glider on the premise that my design will be:
-extremely light (less than 300 pounds empty weight)
-constructed using composites (I plan to use fiberglass in the wings and control surfaces, and spruce for everything else)
-capable of being winch launched (i.e. from the hitch of a truck)
-relatively cheap

I have Daniel Raymer's Conceptual Aircraft Design for Homebuilders and his actual textbook (Aircraft Design: A Conceptual Approach), I am also going through the FAA's Glider handbook. I feel that these resources might be sufficient enough, considering that many concepts from powered aircraft design carry over to glider design. I am wondering if there are any online resources or textbooks I can find specifically for glider design.

Specifically, I'm having trouble with sizing the fuselage and the wingspan.

Thank you all for your help in advance, I look forward to being a part of this community.