My family is originally from New Orleans so we travel there a lot. We have done the ghost tour and the vampire tours in New Orleans. I believe we even did one by carriage (but that may have been Savannah). I have not heard of the one you are speaking of, but there are so many now. There is one of the Garden District, a voodoo tour, cemetary (by day only), etc. New Orleans is a great place to do a ghost tour - its history and the dark streets of the French Quarter at night really lend themselves to this sort of thing. You can even have your palm read or look around in the interesting voodoo store while waiting for one of the ghost tours.
I highly recommend it.