I've done tenderloin steaks, ribeyes, hamburgers, pork ribs and some vegetables sous vide. For steaks I suggest using dry aged, or letting wet aged steaks dry out in the refrigerator for a few days loosely wrapped in paper towels. I like to cook beef steaks in a 130-135 degree bath for about an hour, then let then cool off for about 10 minutes before unbagging, patting dry with towels, coating with oil and searing off in a screaming hot cast iron pan or on a very hot grill for about 1 minute per side to get a crust. Bison is very lean, so you would want it at rare to medium rare temperature at the most. You also might want to look at extremecookingblog.com, he has a section on sous vide and has done more interesting things than I.