Your BEST option to gear up your naked toons is to use your booster in hyjal, like you said. There is no easy way unless you get lucky and find the gear on AH. Your right a naked toon will struggle with Hyjal Quests mobs.

The only downside to boosting toons from low to high level is they end up naked at the end.. but it only takes a few hours of questing in Hyjal to gear them up 8) So not a bad deal!