That’s exactly what I did a few months back, I bought a dfam,the three tier and the 60hp case and thought that’ll do. I filled it pretty quick and a Metropolis on eBay soon meant I had to take out all but one module and leave them on the shelf until I’d chosen and sourced a new case. Rings and Plaits really interested me too but it was the Karplus Strong sounds that I was after and I got those in 2hp thanks to pluck. I would get a mixer as routing any signal through the M32 means it get’s filtered, the LFO applied etc, there are ways around this but they’re a pain. I’ve not had an issue with voltages so far but Erica do the M-scale specifically for this. My Metropolis purchase probably answers your sequencer question, the M32’s isn’t the most intuitive sequencer due to the lack of visual feedback and the number of shift commands, multi button simultaneous presses and LED combinations to remember. A Pamela’s new workout is next on the list and I wish it had been a first purchase when the funds were available so I’d definitely get a good dividing clock generator and modulator in there sooner rather than later. My biggest regret is the 60hp case though, not that I mightn’t have added it at a later date when I had a better idea of how to fill it for maximum efficiency, but starting out get the most HP you can for your money, the Moog case and stands ain’t cheap for what they are. You’ll get 84hp, power and adapter with the tip-top happy endings for fractionally more than the Moog gear, I went with the u-Zeus and was a bit miffed to discover It didn’t come with the wallwart- another 20 quid and three day wait to get up and running and immediately wished I’d gone with the happy endings. Hope that helps.
-- Dom78

Wow, tons of knowledge here! I'm gonna have to read through this a few more times and take some notes, haha.

If I went with the Happy Ending, that would mean the Mother 32 would have to live outside the rack, or else I would just have 24hp left to play with. Not the end of the world, but I would prefer if everything was condensed into one case.

It's looking like I'll be picking up the Mother 32 today and I'll hold off on a case for now until I do more research. I was originally married to the idea because one guy was selling the M-32 with the two-tier case as a pretty good package deal. But luckily, a local music store has a bunch of used M-32's on for cheap due to Black Friday.

Thanks again for your help!