When I used to use ag_unitframes there was a nice collection of pre-made layouts for it. I think it's still available here on wowinterface.
Is there such a thing for Pitbull?
Likely the place to check is over at the WoWAce forums for pre-made layouts. I have never seen someone "releasing" a Pitbull layout. They are always included with a UI or attached to a forum post. There is/was a stickied thread over at WoWAce where people showed off their Pitbull layouts however I don't know if anyone has posted any recent ones.