Ads,
The project looks to have come on a long way, version 3 looks very tidy!
I was thinking about a TC design similar to this, but i don't have the ability to get any of it on to a computer and all my crayolas have all gone missing...anyway...
To keep the weight as central as possible have you thought about using LiPo saddle packs? You could butt these up together under the top deck right in front of the motor. If you place them west to east (as opposed to north to south - does that make sense??) on the chassis you would save a little room and should be able to get your electronics in.
This is what i would have loved to do, but time, money and capability are sadly all lacking
Did the STCC test go ahead? How did it go if you don't ind me asking?
Look forward to seeing more...