What a nice donation! I hope your wife isn't too disappointed that your broilers are not destined for a very long life. Here's a link that may help you understand a little more about them: Raising Cornish Cross for Meat- the TRUTH. Might also be a good idea to check out this forum: meat birds and see how other folks are dealing with their broilers and maybe post your own questions.
Your other hens look like a Barred Rock, Buff Orpington and possibly a blue or splash laced Wyandotte. They should be good layers for quite a while. Great find on the new (used) coop!
Best wishes with your new flock
Welcome to BYC!
You may want to keep broilers separate to maintain breed purity for $1200.00. Then you can sell them for meat and start turning a profit to pay off that bill.