Hens don't lay consistently throughout the year so you can't really expect a specific number of eggs per week.
I have 14 chickens(one is a roo and one is a very old hen - so let's just say I have 12 layers). Right now I am getting about 10 eggs a day. But in the shortest days of winter I was only getting about 3 eggs a week. As spring progresses the hens go broody and that means fewer eggs again.
I think for your situation 7 or 8 nice production reds or something similar would be ideal(you can eat them too if you want).