When I worked at the State Forensic Science lab years ago we had a Wing Lynch processor - you loaded the reels, put them into holders and then into the machine, and it did the rest - heated the chems etc..you could set the time and temp, and it did the rest.....all you then did was used a final wetting bath, then put the films in to dry....you could use 1 X 35mm reel, or up to 8 (or 10?? I can't remember for sure) so it was very economical...

I've seen C41 film processors converted to B&W - it's not all that hard to do once you clean everything, and the machines are dirt cheap (seen several for free here in OZ) now..but the dev times are not variable, and they use allot of chemistry to fill the tanks.....

Also Arkay has a small desk top auto processor - different models could do 4 or 8 rolls of 35mm (same number of 120 if you loaded 2 films on a reel) - they had 4 baths from memory - in the smaller one you loaded chemistry into each storage tank before processing (they were only small tanks - 500ml??). The larger one had maybe 5 liter tanks?

I never got along with the one I tested (for the life of me I can't get the hand of loading metal film reels)...thats why I like the Wing Lynch, as it used Patterson reels for 35/120, and the 5x4 holders were easy to load.....

If you can find one you could also convert a old KISS Film processor from the early KISS lab system - I had a paper processor that was converted to black and white that was good for proofing, and bought a film processor to convert to black and white...only reason I never ended up doing it was that my workflow changed and I found myself using a Jobo at the end of each day.....