I don't have loads of experience with eating 'dual purpose' chickens that are supposed to be OK for eating as well as laying eggs BUT, the duals that I processed were Gross!
With all the types of chickens available to us today, my recommendation is for you to order super fast maturing'meat' birds as well as your slower maturing layers so that you have good eating birds, then also good layers. The meat birds reach great weight by about 8 weeks whereas some of the layers don't grow that large in their whole lifetime.
I think a lot of people just assume that we consume retired layers in the grocery store's meat section but from what I have been able to learn in my researching, we don't eat layers at all from the store.
I think the birds we eat commercially are very young 'meat' birds. If you google chicken hatcheries, you will see that most of them have the chickens divided by layers and meat birds.