First, thanks for the support guys!

sequencing : i Don't know
-- kaas
here are some things to consider when choosing a sequencer:

Do you use a daw? if so do you have an audio and/or midi interface? maybe a midi ->cv interface or a dc-coupled audio interface would be more suitable than an in rack sequencer (at least for now)

do you have other cv-able synths? that you want to sequence too? how many? you'll need to take this into account when choosing so that you have enough channels

do you have midi synths that you want to sequence? how many? maybe a sequencer that does midi as well as cv would be appropriate in this case

do you want to purposefully program sequences? or will random suffice for now?

if only the last answer is yes then pams will work for you - at least for now - this is probably a good thing as it will allow you to concentrate on learning the other modules - a dedicated sequencer can come later

if you absolutely must have a dedicated sequencer then I would suggest getting one with more channels than you think you will need - ie don't just buy one that has a single channel (as just like mixers, audio interfaces and vcas - you will need more, eventually)

in this size case I would want a maximum of 3 voices - otherwise there will not be enough room for the support modules - ie utilities - that make modular worthwhile over a fixed architecture synth - that would suggest that you need a sequencer with at least 4 channels (eventually) - but (and I'm contradicting myself a bit here) you could use less sequencer channels and tune your vcos to intervals - so vco 1 is tuned to C and vco 2 is tuned to G - send the same CV to both (via a buffered mult) - if you use the same envelope for both you are playing 'power chords', but if you use different envelopes for each you can do more complex things

"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia

Utility modules are the dull polish that makes the shiny modules actually shine!!!

sound sources < sound modifiers < modulation sources < utilities