Always start on MG with a case that seems too large. You can always pare things back down on here before committing money to hardware.
VCAs look boring, yes. But they're essential. They're what you MUST USE to create changes in level for both audio and CV/modulation, they can be used as ring modulators (of a sort), they can allow automation of panning, mixing, etc. Lots of people try and get away with one or two...and regret it later on.
That's an expensive case you're looking at, btw; if I configure it with power at 126 hp x 2, I get a cost of UKP 680 with VAT. Then there's this: https://www.ericasynths.lv/shop/enclosures/studio/2x126hp-monster-case-140mm-deep/ which has a much beefier power supply (2.5 A on each 12V rail), better depth (140 mm max!), real busboards, etc. OK, so it's not curvy...but remember: what you can do sonically is the important factor here. Think practicality.
As for the design...hm...let me think about that. The biggest problem is basing this around the Akemie's, because it's such a space hog, but there'll be other ways of making this work...