Try Executive AirShare (Executive Flight Services) @ Fractional Aircraft Ownership | Executive AirShare.

They have a FTW and DAL base (not much at DAL when I left, just a few managed planes IIRC). They were managing a Citation VII (could've been a III or VI, I forget), but who knows if they still have it.

Either way, they're often looking for pilots. Turn over has been a bit high lately due to lots of days worked and most are overnights. Standard company equipment are C90Bs, BE350, Beechjets (400A), and Phenom 100s and 300s.

Hope that helps, and good luck!