I was able to import the glider board outline design into Eagle with relative ease using the inbuilt DXF importer. This includes mounting holes on the board to attach it to the glider.

I have allocated spare I/O pins from the ATMEGA to a set of male headers. Battery connections are seen at the bottom of the board. The three stepper motor drivers are in a row, with each having the motor connections nearby.

I have updated the files section to include the eagle board. I will also purchase a series of boards over the next few days, so I receive them within a few weeks.