More progress:
I made some shelves for the batteries today and did a rough layout for the electronics. I still need to finish my battery packs, add balancing wires and shrink wrap them so they can be velcroed to the shelves. It's a hefty beast, weighing in at 8lbs. 12oz. Unfortunately I'll have to wait for the snow to melt before I can really test it out.
Most importantly, the body still fits :)