Just to take up your last query, Andrew—I believe “Integral Theory” generally refers to Wilber’s AQAL model and its meta-offshoots. One doesn’t find the same term in Aurobindo, Gebser, Steiner, or the other big originators of what we might call “Integral Philosophy” more generally (such as Bergson and Teilhard de Chardin).
You might be interested in Jennifer Gidley’s essay, which we reviewed in an earlier Café, comparing and contrasting the philosophies of Wilber, Gebser, and Steiner.
(For pedagogical reasons, she leaves Aurobindo out of the essay we reviewed.)