looks like a decent start and some decent plans... not sure about the double O&C though! I'd rather have more specialist modules!
first thing I'd add would be an end of channel mixer, with enough channels to accommodate a bit of expansion... this may not be a single mixer - it may be a number of mixers and depends on you really - maybe some channels with panning and some stereo channels (work out how many mono and stereo channels you need based on what you are intending to buy and then add some!
plus maybe some sub mixers - but you'll work out these as you need them (I want to mix this and that before doing this with the output - dc-coupled would be the way to go so they can be used for both audio and cv)
and then utilities - the aforementioned sub mixer(s), a way of multing signals (buffered mult for v/oct, passive for everything else - module, stackcables, headphone splitters etc), a matrix mixer, shades or 3*mia, kinks and/or wmd/ssf toolbox
fx aid xl is a useful module to add as it;s very versatile and has a decent amount of modulation inputs and better ergonomics than the non-xl version
personally I try to think (loosely*):
sound sources < sound modifiers < modulation sources < utilities
as this tends to give the most versatility for the money
*loosely because some modules fall into multiple categories and because multiple oscillators (and sometimes other modules) can form a single sound source - for example your dixie II+, rubicon and a waveshaper could form a single complex oscillator
hope all this helps - have fun!
"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