There are a lot less boxers on the EU side, compared to US. I wish you good luck, but i'm affraid there's not enough animo.

If you're looking for a server with quite some boxers then Aggramar is a nice one, Alliance side. 9 boxers here (including me). We got a channel and can't wait till everyone hits 70. Things like kara and joining AV with 3x 4 shaman boxed etc. are things we surely want to give a try. Since there's only 1 boxer with 4 70 shaman + paladin atm. We're getting close though, quite a few are past lvl 60 by now.