We are looking at going from NW6 sp5 (edir 8.7.1) to NW65 sp8 (edir
8.8.4 or 5), and after some linux training, possibly the linux kernel.

What would be the best, easiest, safest way to go about this?

Would we be better off going to edir 8.7.3 on our servers before going
to NW65, then going to edir 8.8 after that? Or would it be just as
good going to NW65 & letting that upgrade move us to edir 8.7.3, then
going to edir 8.8 afterwards?