I've never had silkies but they're similar to all chickens except that they are a little more delicate and may have trouble seeing. To avoid predators even in a city (hawks, foxes, raccoons), the cage should be fully enclosed. I've lost chickens to both foxes who dug into the cage and hawks, when my mother decided the chickens should go out and play. My page discusses the setup that I have. Silkies aren't too big so for a few of them, an enclosed house [maybe at least 4' x 4' with a height of at least 4' (it's better for you if you can stand up in there)] with a low roost (say 2' high) and a larger run is fine. Make the run as large as you have the money and room for. Our setup is made of wood, plywood, chicken wire, dog fencing, etc. Silkies shouldn't be any more noisy than other chickens. Hens just cluck a little but if you have a rooster, he will crow which some nasty neighbors probably won't like. Silkies are a little bit less aggressive than other chickens but roosters will still defend their girls.
My chicken page is at
http://www.fishpondinfo.com/chicken.htm