OTBVA is the 4chan of the battling world. It's just garbage and memes. RMBVA is cool though. I don't post there at all but their feed for the battle scene is probably the best.

Where could unbiased voters for such a battle be found?

i guess you could do a panel? A few people from both sites.

Maybe we choose the winners based on a poll. And let people promote the battles outside of the site(The drawback being bias. But, the positive being that this potentially increases membership through people signing up to vote. MAYBE they'll stick around.)