what would you recommend be the first, say, 5-7 modules to get me started with?
-- charliechunk
You're getting a lot of advice, but you're the one who knows best what you want to do with your devices. Treat everything as potentially useful information rather than authority. And go slowly!
Of the modules Lugia added, I own the A-138s, Quadrax, Qx, and 3xVCA. These would all be useful immediately (you wouldn't think the mixer would... but Quadrax can provide oscillators also!). Happy Nerding modules are hard to get hold of. I actually use the 3xMIA even more than the 3xVCA; it sits next to some free-running LFOs from one of those boring modules you'll eventually consider. Pam's and Quadrax can attenuate their envelopes/LFOs but neither is convenient to tweak on the fly. I love Frap modules, but I was advised to get the Klawis Mixwitch over 321. It does a lot, and has a nice feature that makes it easy to zero out an attenuverter (though harder to sweep through zero).
Remember that OS 1.3 means your Digitakt can mix input from your modular, pan it dynamically, and apply its effects (and a similar Digitone update is considered likely). Both the Digitakt and the A&H can deal with Eurorack-level signals, but an output module is convenient. I like my Befaco Out v3, which has a cue input to let me audition part of a sound without repatching.