If you want to keep a steady supply of fresh, but not too old, roos for meat, you could invest in an incubator and do staggered hatches. The drawbacks are constantly having chicks on hand at various stages of development. There is no LAW against eating the hens before they become layers, either ... they just don't usually tend to be as big as the roos.
So...if you're running a 50% male/50% female average, you start x number of eggs, say 10 eggs on day 1, 10 eggs on day 7, and 10 birds on day 14. By day 21, the first group of 10 should hatch, and you can start a new 10. 12 - 16 weeks from day 21 you should have 5 chickens ready to butcher - 3 for your family, 2 to sell, and 5 hens to sell (at any early age, as soon as you know they are hens, if you don't want to eat them). You will continue to have more or less this many every week, depending on your hatching success rate.
If you're doing a "planned" rolling hatch of this type, you can't depend on a broody to be available all the time, and I understand most want to spend time raising the chicks afterward, which takes away from their laying for a longer period. The square foam bators hold around 40 eggs, so one should accomodate your rolling hatch, and you'd want to invest in another for a separate hatcher.
Good luck, and good eating!