I just last night finished watching season 7 of TB. Love that show. Coincidentally, I've been on a Uniystem kick again myself lately. I'm not super-familiar with the Cinematic Unisystem (I own them all, have read most of them, but never played) but Classic Unisystem seems like it would work well.I can't think of any either. I have Angel, Buffy, and Eden Studios Presents vol 1. I haven't picked up Army of Darkness or Ghosts of Albion.
Start with WitchCraft. You'll need the Mystery Codex for Vampire and Spirit PCs. Abomination Codex gives rules for Werewolves and Revenants (in case you want to add a little "the Crow" into the mix).
Then grab All Flesh Must Be Eaten and a few supplements for a host of different monster abilities in case you need them.
But WitchCraft and those other two books could pretty much do True Blood without much hacking at all. The only thing you'd need to muddle over are Fairie abilities. But that could probably be done with one of the schools of magic (maybe the dream magic in Book of Hod, but I haven't looked at that one in years).