Would definitely suggest visiting the Muffwiggler site if you haven't already, and individually search for information on each unit before making any purchasing decisions. If possible, there's no replacement for visiting a store that sells modular and getting a feel for each piece. Buying blind just means spending a lot unnecessarily, getting frustrated and having to resell stuff you don't really want.
https://www.muffwiggler.com/forum/
https://www.muffwiggler.com/forum/viewtopic.php?t=106396 // modular synth basics
You might also want to look up some Raul Pena videos on youTube (Raul's World of Synths) to get started:
Good luck on your journey.
NEW EP: https://fastus.bandcamp.com/album/terra-incognito
Latest works: https://soundcloud.com/fastus
Modular studies & sketches: https://soundcloud.com/problivion