The original Pentax 6x7s with MLU seem great, but I hear they don't work without their batteries (or film) and I hate that.
What!? You "hate that"? Steady on, mate. What's the problem??
The battery (singular) weighs next to nothing, and most owners of the 67 carry a spare with them, not in the likelihood of ever needing it on a shoot, but as sensible insurance.
In the 67, the shutter disengages if there is no film loaded. It's a good feature to prevent idiots fingering the shutter just for fun. The function also nulls all controls so there is no drain on the battery. Conversely, if the shutter remains cocked for a fair while, the shutter speeds will become inaccurate. A big problem with a huge number of used bodies where owners have put in film and left the camera in that state for months on end.
Like electronics? Well the 6x7/67 might well disappoint you, really. A couple of resistors, potentiometer, lengths of coloured wire, a capacitor here and there and a solitary battery check LED... and rudimentary construction would probably make it easy for you to replace things ad hoc — no USARTs, decade counters, CMOS, EPROMs or other trinkets to trick up. The majority of bodies are still soldiering on literally in the era of the first Moon landing technology.