Nice start, indeed. Effects are a good suggestion. You’ll have to decide whether you want to use them as a utility or part of sound design, which will dictate the extent of CV control you’ll want.
Suggest you look at Chronoblob 2, Magneto, 4ms Dual Looping Delay, ErbeVerb, Black Hole DSP2, as well as 2hp delay and reverb.

Now, especially for the Morphagene, a CV sequencer would come in hand. I really like the Malekko Voltage Block.
A multi mode filter is also a fairly basic need. Erica Black VCF 2 is nice, and so is the Morgasmatron.
For everything MI, always consider the micro versions (e.g. Beehive vs Plaits).
And: Intellijel 7U case with the Audio I/O is always a great choice. You do need audio I/O, eventually.

Some LFOs would be nice: XAOC Batumi
More conventional envelopes, perhaps: XAOS Zadar