I have an SQ-A and got about two thirds my Bronica stuff off ePrey, the rest from KEH. Obviously there is some risk with the auction site, but with twenty year old camera gear there is some risk anyway. The 40mm lens is less common, and IIRC pretty pricey, I have a 50 mm (PS flavor). The page linked above has some links that will take you to some of what I've done with mine. The 'normal' 80 mm is probably my most used lens, although lately I've been giving the 110 f/4.5 macro a workout.

With the Bronica I shoot about 95+% B&W which has been mostly Tri-X (400TX) and Acros 100 with some Plus-X (no longer made - "sniff" ), FP4+ and others mixed in. I am moving toward FP4+ to replace Plus-X. I process my own B&W and do traditional wet printing so I can't say too much about the scanning work flow, although it's my vague understanding the tabular grain films (Delta xxx, Tmax, Acros) are good for that.

In color I've shot some Provia 100 transparency, but it appears to me transparency film selection and availability is shrinking, and I've not been especially happy with the local processing I've found -- more an issue of bad handling and dirt than color rendition. I've shot some Ektar 100 and Reala in C41 emulsions, but I generally use "other technology" for color.