Sounds like you have a nice set-up planned. I'm sure it will be great, especially since your husband is an engineer. My going on 4 years old 13 girls (New Hampshire Reds, Delawares, Blue Cochins) also have an 8 x 8 coop, but a 360 sq ft run with a top. If I were you, I'd consider making the run bigger if you can. Yes, they will soon start flying out of the brooder, and they won't have the sense to fly back in! I think a production red is typically a cross between a Rhode Island Red and a New Hampshire Red. With golden sex-links, I think the father is usually also a Rhode Island Red or New Hampshire Red rooster and the mother can be any number of silver factor white breeds like Rhode Island Whites, Delawares, White Rocks, and others. And if they are commercial (like ISA Browns), a considerable amount of selection and breeding has gone into the parent lines as well. Campines are beautiful, but I don't think they are used any more in any modern commercial hybrids (although I could be wrong).