OK, after much thinking and wiggling knobs on what is currently assembled, 84HP is just going to be too small for my plans.
I have been doing a lot more planning. Does this look well-balanced?
I found 108HP Vector Rails are sold by Pulp Logic, and I think they are usable with Intellijel 1U modules. The 108 is also just wide enough to fit an extra intellijel 1U tile compared to 104HP.
The case I am thinking of building is going to go next to a Sub37, so I am trying to match the shape a little bit:
http://prntscr.com/k1t8n8
http://prntscr.com/k1t99h
sorry for the wonky links, I don't know how to show pictures here...
The bottom is at a 10° angle, and the back is at 25°.
These are the modules I have so far:
Basically the functions I am looking to get in the next 100HP are in order of need:
Attenuation, Touch Controller, Multimode Filter, 4X VCAs, Scope Utility, 4X LFOs, Logic, Rhythm and CV sequencing, Precision Adder, Utilities, Buffered Mult.