Just treat the rack as a plan - and plans are great until you start to execute them - at which point they usually change
I think aesthetics are personal - I have a mix of red, black, aluminium and clear paneled modules - i'm more interested in what the modules do than what they look like to be honest
If I were to add modules I would add the following (you will need the bigger case!):
mutable links and kinks - an excellent utility starter set
a quad cascading vca - I like veils it is simple to use and has enough gain (20db) to act as an external input - you can also use it as a voltage controlled mixer (hence cascading)
a disting - either the ex or a mk4 - always there when you need it - if you keep using it for the same thing - buy a module that does that and use the disting for something else
a matrix mixer - there are a number to choose from - I'd probably go for either the AISynthesis one or the Doepfer
the usual advice is to just buy a few modules to start with - learn them and how they work together and then add other modules slowly - if you are in any way worried about being overwhelmed - this is definitely the way to go
maybe you should just get one vco, the filter, the modulator and the vca waveshaper ringmod - and seriously think about adding a few of the utilities above (links and kinks, maybe veils, maybe a disting) learn how to patch those together and then try to work out what you are missing - it might even be from your planned rack - who knows?
"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