I know it's almost identical to the enGB but, in all the years I've played WoW I have always preferred the first one because in addition it has a comfortable name randomizer in the creation screen of the new PGs.
And this peculiarity is pure gold for the more demanding "nerd" players who do not want to lose entire days to choose a good fantasy name for their own pg, in view of some roleplay maybe (and I admit to being one of those xD)

P.S: it is actually now easily found on pi**tebay (guess what) typing "world of warcraft 1.12.1 enUS" [it's the first one, about 373 seeds btw]
To the Admin/Mods: I know that (in theory) I should not advertise warez in any case, but I hope I can be partially excused since it is an alternative client to play in the future on Nostalrius.
If it is not compatible with this post and causes any trouble please kindly remove it if you find necessary to do so.
Hoping for your understanding, I'll wait your denial / confirmation, thanks
