Just go to OpenRaid and sign up for the multiple runs organized. I try to do 6 runs a week and so far I managed to get people their transmog gear within a week.
I know many people prefer not to take newbies, but I rarely had any problems with inexperienced people.
I'm not sure this is the right forum, but I just wanted to reach out to players who desperately want their Challenge Mode armor but lack the people on their realm.