I'm into the RB 67 as well. Like you, I'm just getting back into film photography.
When I went digital, my monochrome preference were Ilford's delta films - 100 & 400. I do not know what developer was used because the processing was done by a pro-lab with instructions to process for fine grain, slightly high contrast, and good detail. Whatever was used was great. But the lab no longer exists and what they used is lost to me.
I have heard great things about cafinol developer and am setting up to give it a try.
I'll let you know the results after some experimentation.
Dangerous to oneself