Hi Zuggamasta,
I am myself not so much (not at all ;-) ) into DIY of modules. I solder my own patch cables but that's about it.
However besides Befaco, manufacturers like Erica Synths, Bastl Instruments and Polaxis have DIY sets/kits. Naturally there are many more manufacturers, it's just that I don't have experience with them.
Have fun with the DIY part and kind regards, Garfield.
For review reports of Eurorack modules, please refer to https://garfieldmodular.net/ for PDF formatted downloads