As long as you are going as low as is possible for you (so hams touching calves) then i dont think Hamstring work is definitely needed, calves maybee just 3 sets per week. It all depends on your goals. if its strength then i dont think its definitely needed as they will get strong in the motion that you are training them anyway. If it is looks then possibly, depending how hard they are hit during the squats, as everyone is different to how much the hammies become involved in their squat.
TEAM CROM (supporter) !!!!