it's ok as a start - but I think you need more modulation sources and utility modules, for balance and variety... see my signature for some hints in that direction!!
re utilities: more mixing - for both modulation and audio + panning for audio would be good (could be handled with more vcas), which you might also find you need... I like matrix mixers for modulation sources - put 4 copies of 4 in and get 4 more related, but different modulation sources out - I'd also consider some basic sub-mixers - possibly something based on the moog cp3 (manhatten analog for example)
I'd consider replacing the Tempi with Pamela's New Workout - better for modulation purposes that tempi.. and smaller learning curve (no pain in the ass button combos) but there is a simple menu structure instead - and it will add some useful things in there - basic logic, pulse width manipulation, different waveforms etc that I'm not sure tempi does
you might also want to look at a simpler filter - they're always handy to have - doepfer make some good inexpensive takes on classic filter topologies - the sem and wasp are particular favourites...
I'd also be tempted to get something like the fx aid pro, or xaoc timisazora instead of the noise engineering effect module - more variety more easily...
6u case is a good starting point - Mantis is a great case!!!
I'd go slowly at first though - get the minimum that you think for a single voice... and don't forget some stackcables...
"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