I'm thinking of modeling them as Thousand Sons, on account of their unit-wide invulnerable saves and slow & purposeful USR, plus because I have a unit of those primed and the upgrade packs are pretty easy to acquire. I finally managed to snag a peak, and, while it doesn't fit what I need for my Minotaurs, I was thinking that they'd make amazing Chaos Marines and then I could make that CSM army I've been wanting to field, despite not actually having any CSM. I didn't really realize they had a codex (given that it was never printed and I haven't see anyone field it). Someone suggested the Legion of the Damned codex for allies in that Minotaur thread of mine.