New guy here, but have been on the circle frequently and am a big Virtue fan. Love my decked out 901 and One.2. Anyway...........
Esthetically, if the choice were up to me (a professional Industrial Designer) on the "larger" dac platform, I'd go with the full Melissa size, not a half-height Melissa as some suggest.
This way it will look great stacked, or in some cases (like mine), sitting next to each each other horizontally in a long rack / shelf. Another advantage is that Seth can offer the gamut of outer case options to match everyone's desires. That'd be a win / win for most everyone I would imagine.
Another thought (and I think this would be really sweet) would be to perhaps offer the half height Melissa DAC, but also a matching half height Melissa Power Supply case that can be customized to hold batteries, linear supply etc. Stacking the 2 would give you a full height Melissa. Along those lines, perhaps the full height sides can be used to hold the separate DAC and PSU cases together as a single unit. Again, this would allow for uniformity of size across the line and customizing options.