Pass on prefabs. They are nothing but trouble
They can only hold a fourth of the birds They say, underventilated, not predator proof, and are made cheaply.
A coop should have
atleast 4 sq feet per bird in the coop, 8 sq per bird in the run, 12" linear per bird for the roosts, 1 square foot per bird in ventilation, and 1 nest box per 4 birds.
https://www.backyardchickens.com/articles/categories/large-coops.20/
A chicken lays every 26-29 hours at the most, most lay an egg every other day or longer.
I recommend brown leghorn, prolific layers with good feed conversion.
For eggs for 8 people, plus to sell you'll need about 20-25 birds and cycle every 2 years.