My favorite healer that I have ever read about, EVER, was in the book Shadows of Socrates. Instead of healing through divine intervention or magical prowess, he absorbed the injuries and then healed them within himself at a much accelerated rate. The image of someone standing over an injured ally and bandaging themselves before taking on their wounds seems pretty mythic to me. And the quote... "I hate broken bones."

In a more mechanical sense, give the anthol 2d6 or even 2d8 hit points per level, and their intrinsic class ability should grant fast healing equal to maybe 1/3 of their level. Also they can take on the wounds of anyone, but in an "all or nothing" manner. The progression of this might give you some DR against your damage absorption, with the caveat that the damage can never be reduced to zero.

I really like the heal check mechanic you have, too.