WoD or Cata (for non-allied races so they can do tabard rep from dungeon spamming) seem the best expansions for this.
And the best class to do this as fast as possible is Hunter.
… I’m about to have a Hunter of every race at 50 and all allied races with a WoD garrison.
At the very least I have enough transmog pieces to make them look good and unique even if Mail usually is less impressive than other armor types.
That means you have to play a Mechagnome.
The hardest thing to do in WoW.
I’ll cover their face.
Won’t be enough.
I gotta try!
If only they could be Druids…
He has a good chance as the mail heirloom melds enough with the tabard. That would allow him to carry a helm from the beginning. 
theyre like sixty percent face.
Fortunately, gnome ears can be squeezed into helmets.
Strange concerning how piercing elven ears and eyebrows are. 
