Potentially wanting to reroll horde after playing alliance since classic day 1. Had some questions.

Hey everyone. I am playing Alliance on Whitemane(TBCC), and am thinking about rerolling horde. What would be the better thing to do: Trade my gold to horde toons on a new account on the same realm through neutral AH? I could also boost a new 58 horde doing this, so it could be much faster to get through with the reroll. Or is the better option to trade my Alliance Whitemane gold with someone to Horde gold with someone on a different realm and start my horde characters there? Also, are either of these methods against ToS? First time considering something like this so I want to be sure it is 100% okay with Blizzard.