Hi there and I am new since last year with similar goals.
Here are my recommendations and tips:
- Get at least one Harvestman/IME synth voice module like Piston Honda or Hertz Donut. Thank me later
Filters- I like Harvestman/IME Bionic Lester since it has lots of infinite tone shaping options plus use presets
as well as lots of filter types from high pass to band pass. Another candidate would be Dual Borg love that filter.Sequencers- super important I found for melodic options. I have a lot and found something like Eloquencer or Black Sequencer or Vector to be ideal because you can create and save presets for your melodic patches as well as create random, reverse and quantized scales without needing a separate quantizer module.
Utilities/tools- the less fun but crucial modules. You want mults, VCAs, sequential switch, logic all key for crafting unique patches. I like the Mutable Instruments Kinks and Links pair of modules for this in a small setup. Our very own @JimHowell1970 here turned me on to these functional modules and I have zero regrets. Another fun support module that I like is Tool Box from WMD/SSF which adds spice in small rack as it has logic, rectify, compare and switch all in one small HP module! Attenuators are super useful especially when using percussion and melodic patches. I like my WMD 4TTEN module since it has 4 sliders that are super ace for live performance with patches that can let you play your modular controls like an instrument.
Mixers- I started with a small 8 channel external K-mixer and love it but once I got a mixer dedicated for in box eurorack, I was hooked! Nothing beats the flexibility and ability to mix cv and audio in your case. I am a big fan of WMD Performance Mixer and Befaco Hex mixer and been having fun with my XAOC Devices Praga mixer. For a small mixer, I like my Intellijel Mixup and you can chain them together as well for larger mixer.