is there a particular module of the above that I should make sure to get first, or early in the process?
-- HGsynthAll of them.
But I would start with Pamela's New Workout and Ornaments and Crime. You're at about the $500 mark with purchasing those two. I would get them to familiarize myself with their operations. You should be able to use them with your MiniBrute and Model D. Those two modules can do quite a bit even though they aren't on the "sexy" list
-- Ronin1973
Maths would be another that you could potentially do a lot with your Minibrute as well (and has a pretty good learning curve to it as well so getting a head start on learning it is not a bad idea)...when you get Maths, do a search for "Make Noise Maths V2 Illustrated supplement" and bookmark that sucker.
Also, not to complicate things, but ornament and crime has an optional firmware called Hemispheres (which I installed) that essentially allows you to split the module in half and support two simultaneous applets with different functions at the same time. It does overwrite the original firmware which you can easily reinstall but you might want to take a look at what it offers here: https://github.com/Chysn/O_C-HemisphereSuite/wiki versus the apps that are included on the original firmware here: https://ornament-and-cri.me/
JB