Finally got my rank 10 Brawler achievement yesterday, did it in 517 ilvl so it is definitely possible. Here's a link to my armory for proof http://us.battle.net/wow/en/characte.../Ratdog/simple
Here's a link to my How-To guide I posted on WoW forums: http://us.battle.net/wow/en/forum/topic/9572937765
Happy Brawling everyone, I am very happy