you can go to a couple commercial bottlers who will sell you a base that you modify yourself or w/ their help. they will then bottle & label it for you & do part of the marketing. i can't remember the names right off hand but it's on history channel's modern marvels-bbq tech every now & then.
they usually do batches of 60gal minimum.
Blues_n_Cues BBQ Concessions & Catering