Hi jdesole,
I had an interesting back-and-forth with Jim here on my first ideas for a modular, just like you. Jim is 100% correct about the utility modules. Make sure you get enough VCAs, multiples, etc. I have only a few sound sources but I'm already adding 8 more to the 8 I already have. That's because my current 8 can also be used as mixers and you'll need plenty of mixers and attenuators. And attenuverters. And, as I said, multiples.
Another tip: start small. I was looking at the Harmonaig as well, but I decided to start monophonic. That was a good move. For drums/samples, I have the Squarp Rample, which is small and very powerful. I would advise you to look at it. I only have 1 Plaits, 1 bOSC (analog oscillator) and a Feedback Static noise generator. But I've been having a lot of fun mixing analog waves modulating them in several different waves. I've now done a short track with the noise with envelopes for drums (nice old school) and the Rample is doing some bass percussion. I haven't even received my FX Aid and I have only 1 filter and 1 LFO (not really - my envelope is a Xaoc Zadar that I can also use as an LFO). So I'm finding it's much more flexible than I expected. I'm having a lot of fun expanding beyond what I assume are limitations, by creative patching.
You can check out some of my jams in this playlist . Everything was made with this rack. Of course, with one track per day, it's nothing spectacular, but I think it shows some of the flexibility of even a limited setup.
