Here's how we do it (been doing this for over a year now - vending just like you) and it's been working great for us.
We trim and inject each brisket. Rub and put on smoker @ 225*.
Next - when it hits 160* - we foil and add beef broth. Foil tightly, put in a full pan and place back on smoker (this keeps any juices leaking from the foil in the pan for use later..)
Cook to about 192* then keep in a warmer or on a smoker set at about 150* - keep it foiled and whole. Then when you need to pull it out of the warmer - slice/chop (however you want to present it) - then put in a pan, add as much au jus from the foil into the pan and hot hold/serve.
This same method has been working great for us - hope it helps you and someone else :)