Yes, H8 is the latest. I bought my Galaxy two months ago, it had an ever older version (G-something; it's a code that can somehow be converted straight to a date).
I would say the easiest thing is to use Odin -- but then again I only had the PC suite installed for like 15 minutes, I was appalled by its "blingy" and child-like style.
Mind you, to go to H8 you need to apply the H7 update with a bunch of files, then once more with a single H8 file.
I have no idea what exactly you're missing, as I couldn't find a change log, but there are bound to be a number of bug fixes and suchlike issues.
Good luck with it!
