one of the problems you are going to have is having live in the right sizes at the right times a litter of pups only stays what you would consider "smalls" for a short time. Personally i would start off with more females then you think you would need. Strange things happen, you cant always count on a litter from each female every 22 - 24 days like clock work every time. Even if you do wind up woth more feeders then you need you can always kill off and freeze the excess. If nothing else its always faster to downsize a colony once you find you have too many then it is to expand if you find you have too few. Bottom line is no matter how much research you do there is a learning curve involved and it takes time to esablish a self sustaining colony.