Safety of Sous-Vide for long cooking times
The reduction or elimination of pathogens in cooked food is not simply a factor of temperature, but a factor of temperature AND time. Lower temps typically mean longer cooks.  This changes the texture of the final product.  Sometimes to the point that people find it unpleasant to eat. You will need to factor in the thickness of the cut, and the desired effect you are looking for, in order to determine the length of your cook.  Your best bet is to look here for a comprehensive treatment of the subject.  In fact, Baldwin has a short section on brisket.