With a few years of Modular experience under my belt now and knowing what I know now, this is what I would start out with if I was starting again, I'd pair this with an Arturia Beatstep Pro for sequencing for some instant analogue gratification.
You could save some money with cleaper effects units.
3x Sound sources (2 complete Voices + STO so you have some nice sine waves and some wave folding)
2x Mixers (For mixing your Sound Sources and Percussion)
3x Percussion sources (You can get a good kick out of the ADDAC 103 as well as incidentak percussion)
2x VCA (Small form-factor dual VCA)
1x ADSR (So you have more control if needed and mainly use for the STO)
1x LFO (Everyone's fav LFO)
2x Effects (Delay and Reverb)
1x Power
Enjoy your spare HP, don't rush to fill every last space, this is not like filling sticker books. Resist the urge to 'complete' your rack, its never complete so just relax.