Maxx, what do your parents say about all this? Are they helping you with contacting the state for testing?
I have to agree that you should not bring any birds into this till you know what you are dealing with. For instance, bleach will not kill cocci, but ammonia will, so you need to know what the problem is. You must know what you are disinfecting for and how long the coops should lie dormant (stay empty) before you can continue. And you need to be careful with chemicals you use (like do NOT mix bleach and ammonia! Poisonous gas).
I think you're putting the cart before the horse here, meaning you need to get this disease issue squared away before you bring new birds in and possibly lose them, too. As far as breeds go, we'll talk after you get some information about your health issues with the flock. Both are great breeds, but it won't matter if they die like the others.