Most starter feed I have seen is crumbles. I think most stores sell it as grower/starter. If you can find seperate grower you can switch to that at 6 weeks old. If all you can find is starter/grower crumbles, feed it until 20 weeks or when you get your first egg; whichever comes first. Then feed layer pellets.
The difference between feed for egg layers vs. meat birds is the meat bird's feed has more protein to get them to a large size in a short period of time. It also shortens the bird's life as their body outgrows their internal organs. If you want to keep them as layers, you can feed them the same feed as your layers.
