

I found Brakke especially helpful for thinking about the relationship between Thomas and Gnosticism (I gave an SBL paper called Five Theses on the Gospel of Thomas and the first two theses were to distinguish between capital G Gnosticism and small g gnosticism, based on Brakke) and for lecture 10 on "Re-unifying the Self" in Thomas.

The audiobook is a bit pricey to buy, but many libraries have it (and others in the Great Courses series), and I believe it's available from Audible for those who are subscribers.

I’d like to recommend the audiobook Gnosticism: From Nag Hammadi to the Gospel of Judas by David Brakke (Professor of History, Ohio State University) from The Teaching Company's Great Courses Plus series.
