Hello Bucket.
Nice new coop and run eh!

If it's a cheap Chinese import cancel the order asap, as they are crap. They are flimsy and will warp and are a perfect place to get red mite in..(You'll get to meet some of these next summer).
Look at this like your getting your first car.
Nice new garage and drive, so what do you do?
1. Go down the scrap yard and get some clapped out old rust bucket that leaks oil over over the floor.
2. Go to a car auction with the slim hope of buying a vehicle that hasn't been clocked or chopped or knackered by more than 1 previous owner.
3. Go to a reputable dealer with good feedback from satisfied customers.
Leave ex batts alone, they are clapped out and carry all the viruses picked up in their miserable short lives, pumped full of god alone knows what to make them lay eggs and stay alive. The last thing you need if your a new keeper is a batch of these dumping contaminated excrement all over your nice clean ground.
Same as above for auctions and free- add papers.
Quality birds will cost you more up front, but in the long run you will save money.
Find a decent breeder (There are still a few about that won't rip you off) and buy some nice birds.
Buy them all from the same place at the same time and don't add to them from another place or you will get problems.