I think that, seeing as where this is going, I'll have to secretly make them alternate character sheets for Feng Shui.
All of these ideas will work. Now, I just need to describe how they meet. I'm thinking in a motel, outside of Vegas, where they find a dead alcoholic underneath a prostitute who professes her love for him. Then, they have to investigate the deadly cult which may have killed the man by following a series of clues that are encoded into simple, everyday things and require an extensive knowledge of esoterica.
Then, when they think they're doing all right, they need to steal a car and smuggle it across the border, full of illegal firearms so that they can shoot the monsters who have taken their daughters hostage.
I might also include a bunny full of microfilm, cocaine, and souls.