I'd suggest to get the case and then start building it up from there. I had a good time slowly and steadily filling my initial 98hp and can already use it for my kind of tunes.
One suggestion for your row of VCAs there are some 6x VCAs like the zlob CNICURSAL VCA you need 2hp more but I'd argue you get a lot more playability. The 2hp trim pots right next to each other are close to not manipulable with jacks connected. Also you get a sum out so it acts like a CV controlled mixer, too.