Lots missing here...you're going to need VCAs (both for audio as well as CVs/modulation), for starters, otherwise this will turn into a pointless exercise pretty quickly. Maths is also a useful thing, and you might also look into a Batumi for straight LFOs. Also, if you're insisting on using the Chord as a VCO (I wouldn't do that, frankly), you need to consider a second on so that you can detune them against each other, do sync, etc for a "bigger" sound. That'll be spendy, though, at about $600 for a pair of poly VCOs...which is why I said I wouldn't do that.