OK, I have some progress here.
Housing will be a 1/8" aluminum box built out of sheet and 1" x 1" alum. angle.
In the bottom are the 6 individual packs of 30 - 18650's. I found some shrink that worked really well with them. All leads are 10Ga. Silicone, so there shouldn't be much resistence in the power line. And of course, we have our balancing lead.
Each pack is connected to it's neighbors using 4mm bullet connectors. This makes it removeable and can be configured in a number of ways.
This configuration is for 6S.
To add some cushion, I located a camping matt at Wally World pretty cheap. 2 layers of this surround the packs, then a "lid" is placed on top of them to create a "floor" for the electronic compartment.
