From what it appears, the 53C80 chips should be identical regardless of any suffixes since they're the same CMOS-based 5380 core. I mean if you're stuffing it into an SE/30 it won't be getting any signals faster than 16MHz anyway (and only 8MHz in a Classic). The other thread referenced above seems to have had problems greater than a questionable SCSI chip so I'm not sure it adds any value to the discussion.
I think the original confusion was in compatibility with the original 5380 and the updated 53C80 design, and apparently there isn't any owing to a different pinout (and likely different voltages and other signals owing to the CMOS design).
Short answer: all NCR 53C80s should be compatible with one another, including Zilog (and other) clones, but in a very high-speed application you may need to look for one with a particular suffix.