I'm planning my first DIY case to go bigger than my current Intellijel 7U. Below is what I currently have in there. I'd initially migrate all that and add a few modules, then expand as time progresses. I'd also keep the 7U just in case, for later.

MG says this has a power consumption of 1740mA on the +12V, 830mA on the -12V and nothing on 5V. That makes me completely confused about PSUs like the Doepfer PSU3, which they use on their monster cases. They spec that PSU at +12V/2A, which is barely enough to feed my 208HP. Then -12V/1.2A which is a bit of margin. And then +5V/4A. Why? It doesn't make sense to me at all.

I'm aiming to get 500-600HP. To get to that size, Doepfer ships their monster cases with 4 PSU3s, which gets them 8A on +12V and an incredible 16A at 5V that sits completely unused. I'm not saying there are no modules that use 5V at all - I've filled a 12U monster rack on MG here with some random ideas for modules and I'm at a full total of 4A +12V, 2A -12V and... 215mA +5V. Yeah!

So instead of that, I'm looking at the Konstant Lab HammerPWR set that has +12V/5A, -12V 2.5A and a much more reasonable +5V/2A. Still considering to get the pack with 2 or 4 bus boards. With 2, I can extend with a third at a later stage and save a few bucks. With 4, it's more long term thinking, which I already noticed is a good idea in Eurorack. The 4 bus board pack costs the same as 3 PSU3s by themselves (no power brick, bus boards, ...)

ModularGrid Rack

Modular playlist on SoundCloud - One Track Per Day