I Am Looking To Expand My Hen's Egg Yeild To Begin Selling Thier Eggs. I May Also Purchase More. Can You Help?

I Already Have 6 Large Hen's (Bull Rocks I Believe) And 3 Bantam's, They Produce An Average Of 2 Eggs A Day (Not Too Good). I Would Like To Start Selling Their Eggs, And Also Buy More Chickens. Can Anyone Give Me Some Advice? Perhaps A Suitable Breed, Living Conditions, Specialist Dietary Information. All Help Is Much Appreciated, Thank You!