You said pretty good light; does this mean that you intend to shoot by available light, or using an on-camera flash? Overhead lights in the gym will produce dark eye sockets, so I would suggest that you use flash to more evenly light their faces. If not, then the 35 f/2 would be nice and light, and easy to hand-hold at the slower shutter speed that you may need. Probably try starting at ISO 400 and see what shutter speed will be needed to shoot around f/5.6 or 8.I would suggest shooting around /5.6 or 8 for the needed depth of field. I usually arrange the team in two rows, at the free-throw line. (Two rows will minimize the need for very deep depth of field.) Using on-camera flash, my usual lens is the 24-105.