so which case are you looking at
I'd seriously consider keeping the doepfer, getting rid of the pitts and it replacing with a couple of mantises, it's what I would do if I were you knowing what I know - if I ever buy another case it will be another mantis - best combination of cost/hp/good power/reputable company/standard screws - so knurlies! or just going DIY - and building a 12u/104hp case - I use befaco excalibus power supplies for my DIY cases - which are not that p0werful, but are good power - you might need 3 for 12u/104hp depending on the power draw of your modules
re utilities: take a look at my signature - it's a philosophy/concept for getting the most versatility for the least amount of money... not that I necessarily strictly follow it - or expect anyone else to, for that matter - but I do try to and I do hope that people take notice - because it does work - want more complex modulation - get a matrix mixer and some mults, want more sounds - get a new filter or a waveshaper or delay and parallel process the sound sources you already have... etc etc
*good power for me is clean enough up to video rates - as I do a lot of video synthesis - and need ripple free up to MHz for that not just the 10's of KHz needed for audio
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities