I can see no way a sous vide machine works for you. You really need some form of holding oven or chamber, that will hold the meats at 175F or so, that will allow you to keep pans of meat covered in foil for service. In terms of your cooker, it is too small for any level of vending BBQ. I hate to be a negative on this, but, it will be miserable to vend if you do not have the right equipment.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"I'm Armenian...perhaps...but then again...maybe not..."