well it's not really a modular synth is it? it's a collection of semis in a case with a few modules to bulk it out... as a modular synth it's shit...
at least one of the semis (probably more) have their own cases and power supply - use these otherwise you are increasing the cost of them by 10-20% and taking up rack space for actual modules
the other disadvantage of these is that you are not levering the advantages of modular - use this filter with this oscillator one patch and the next use a different filter with that oscillator.. etc etc
how are you going to sequence? use the mom? ok well there may be issues there iirc mom uses slightly different pitch scaling - so you'd need something to translate - or the octatrack? does it have cv outputs, idk... oxi one? no need for the buffered mult (buffers are generally only needed for pitch)
how are you mixing your external synths - I would not bother with an eoc modular mixer in this case... I would use the external mixer - which you might need to upgrade - but it will be less expensive...
falistri - urgh - imo - bad layout etc - get a maths instead, better learning documentation is available for it - see the 'maths illustrated manual' as well as the plethora of videos on you tube
on top of this, not enough utilities, not enough modulation... see my signature for hints on how to create racks that give the most versatility for the least cash...
1u - I cannot convey how wasteful I think it is (not necessarily a popular ideology) - in terms of cases they cost the same as 3u (or so close as to be irrelevant) and an extra 2u takes up about 3" and means you can fit way more functionality in the case - if I was given the choice of an intellijel 7u case or 2 mantises, I'd always take the mantises...
"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