ok looking a bit better... comments on the last revision only...
MISO is a great addition but primarily as an attenuverter (scale/invert) and offset (both really useful) but mixing on that module to me is an after thought - as you will probably be using the other functions more often for modulation...
are you intending on using the peaks clone for modulation?
what are your intentions for o&c - I find a lot of multi-purpose modules get used for one purpose a lot of the time... if you are intending this as a modulation source I would personally go for a better modulation source - if you are intending on using it for modulation (as well as the peaks) then you might want to consolidate and get a dedicated quad modulation source instead - batumi for example...
the pico trio:
I had a pico seq... to sequence chord progression changes on my sinfonion - hated it... tiny and awkward to use (especially the reset) I wouldn't really recommend any module under 4hp... especially not next to each other unless jacks only or mostly set and forget...
do you really need an output module?? I've never needed one in 7 years... I started with a small in rack panning mixer that had a headphone output built in, then went straight into an external mixer (small yamaha) that was fine with modular levels as a lot of newer mixers are and now use a tesseract tex-mix mixer, which has headphones built in and when I use speakers send the master of that to the yamaha...
I'd seriously lose the pico vca - again - get a full size veils clone!!!! it's a proper investment in your modular!
if you still want the rackbrute keep the lpg - to even up the hp usage, if I remember rightly the rackbrute is a weird 89hp or something...
if you go for the mantis & you should then you can get a bigger lpg... an optomix for example... which have more controls and better ergonomics (see below) and seem to be available again... and I'd also look to add a second vco (possibly another ona) and a better submixer(s) with controls for - possibly something modeled after the moog cp3 - adds a nice bit of grit when driven - AISynthesis Hamonic Mixer for example - I'm considering adding another 1 or 2 analog oscillators and will want to add 2 or 3 of these Harmonix mixers when I do...
ergonomics: newbies often don't realise just how small eurorack modules actually are... 1hp = 5.08mm (or 1/5") - accessibility to modules & controls is important... & your fingers are about 4hp wide... bigger cases and bigger modules are better because of this...
"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