Here's EoV's, but they seem to be looking primarily for DD rather than healers now.
http://eveofvictory.com/
Another one I'm familiar with is CLOVERSbis, but that's because my Best Friend is in it. They're a Global HNMLS, but I don't know if they're accepting anymore White Mages. Most people seems to be Rank 10 and have multiple level 75 jobs, so requirements might be even more stringent than EoV.
There was a third I knew about but it's been permanently disbanded due to too much conflicts.