Hi Ronin1973..... looks like you are vaguely my age, i.e. not feeling old but beginning to feel broken in various places!!
I've got a plan, its evolved a little as I've discovered what I can do with the limited bits I've been able to purchase so far, I'd say that I'm 2 purchases away from buying a Mutable Blinds (for the Quad VCA / attenuverter).
Funnily enough I have my 2hp modules spaced apart by 2hp as it takes about 30 seconds of knob twiddling to realise that a rack of 2hps right next to each other is about as stupid and unusable as it gets, though the features of the 2hp do seem to make them look more appealing to similarly priced but more-hp modules so i keep circling back to the idea of 2hp.
Next up 2hp Bell and a Pittsburgh Modular Micro Sequence... then the VCA's and LFO's and maybe something like the Noise Engineering Sinc Defero Buffered Quad.
I love the 'look' of the Happy Nerding Mutes too but I don't see me having a use for it yet until I have more voices in my rack ;-)
Cheers :)
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.