You've made good choices! I agree with the advice to get a filter. My first was Three Sisters, and it is still the one I use the most, although I also have and recommend the Doepfer A-124 Wasp, Make Noise QPAS, Erica VCF1 and MMF by 2hp. Also, get yourself an LPG--for delicious organic VCF/VCA functions. I love both Optomix and LxD, but there must be many more out there.
Since you are interested in modular synth education, you will benefit greatly from an oscilloscope. You can buy a free-standing oscilloscope that won't suck up HP in your case, but it will clutter your work station. I really like the ZeroScope Oscilloscope which I use all the time, to study audio waves, envelopes, and other CV.
It is brilliant that you have included the Disting Mk-4, which is a Swiss Army Knife (or Leatherman). I use an 8 HP version of Ornament & Crime much more than my three Distings. They provide different functions. Consider getting an O&C with the Hemisphere Suite alternative firmware.
One last addition to your case would be a source of random voltage and S/H. Yes, PNW will put out random CV, but the workflow and responsiveness is not at all the same as with Ultra Random Analog, Richter Wogglebug, or NanoRand v2. I recommend all of those, and URA is my favorite by far.
Then, patch like crazy for six months, and keep notes on what functions you are missing (effects, delay, sequencing). I have the Arturia Keystep, and never use it. Have fun!
p.s. Get a 1U x 6 HP Chaos tile from Nonlinearcircuits. Your 1U module choices are also brilliant.