I'd be checking the date of whatever you're reading. Are you sure it's not dated around the time this phone was released ? If it is, that would explain why that firmware is recommended (may well have been the only firmware available at the time).
Essentially, firmware is firmware, the differences between them are minimal - only differences are the modems, and carrier-specific 'crapware'. The kernels are sometimes a little different depending on date of release (maybe different Linux kernel version), but the main differences happen when you're talking about roms with different Android versions (GB-ICS-JB). Even then, I'm not seeing why you need a specific firmware for an EFS repair/IMEI re-write.
Up to you what you do, but as I said, expect to still be looking for this firmware weeks from now if you insist you need that & only that one.