It sounds like you already might produce enough for the snake.
I breed my fancy mice for pets and food. I have a lot more snakes than you to feed but typically I'll make several passes through a litter. First when the litter is born I remove about half to feed my little snakes or to build up a surplus for snake breeding season. Next when they reach fuzzy size I'll cull the less fancy ones. Most of the time it's self black or grey ones. The third pass is is hopper stage and removing extra males or ones that aren't good with being handled. Late hopper stage I decide who is future breeder and who is getting sold as a pet.
As far as what size to feed to what size snake there is some good info in this link.
http://www.cornsnakes.com/forums/sho...d.php?t=145515