The guides are outdated. Philosophy isn't in the game anymore, it was removed in patch 2.2. I'm not really sure of the fastest way to gear up a fresh L50, but Crystal Tower drops i80 pieces and 100 myth a run, and as a healer you queue times should be decent. Do your dailies and few runs of that till you have the ilevel for Coil 1-5, which has a chance at i90 gear. The myth you are earning can also be turned in for i90 gear.