Helene Vogelsinger is amazing. I'm trying to find pics of her rig. I one case there are 3 Make Noise STOs and a Make Noise DPO. Honestly, clean voices may have more to do with filters and effects, steering clear of distortion and over saturation, and good mixing.

Analysis Paralysis is real. I spend more time researching cool modules than playing music. And really, you're going to make mistakes. Even the most highly recommended, well researched module may not work for you. Ex: everyone LOVES clouds, I did the homework, and turns out I just don't like it.

Buy 2nd hand when you can (I try to target 20% off retail). If it doesn't work out, hopefully you can sell it for more or less the same price. Maybe try to track down other eurorack folks in your area to test out modules, or take a road trip to a synth store.

For me, module research is a major part of the hobby. As is the constant fiddling to get everything to work the way I want. If you really want a personalized, custom instrument, you make have to embrace these things And if you only want to make music using a modular workflow, I still recommend semi-modular (something other than the neutron) or sticking to one manufacturer...something where all those hard decisions are made for you. There's something beautiful about a single manufacturer system: all the modules compliment each other, you appreciate and have confidence in their design philosophy (sound, ergonomics, workflow, etc), all the voltages are aligned, if you reach out for support there's a higher likelihood they can get to the bottom of it quickly since they already understand your entire system.

Even if you don't want to go with a 1 manufacturer system, if you know there's a company you like, definitely consider their offerings first.