I currently have four silkies with the rest of my flock, which consists of both standards and some other bantams. They all get along quite well. In fact, one of my silkie hens is at the top of the pecking order.
To introduce them, I separated my coop with a small fence, and put my silkies on one side and the rest of the flock on the other. The silkies were quite young at this point, so I let them grow until they were almost full sized. They could see the other chickens quite well, and the standard sized flock would often fly over the fence to visit. At first, there was some pecking, but eventually it got sorted out and never became too serious. Once the silkies were big enough, I left the gate of the fence open, so the whole flock could come and go through both sides, but the silkies still felt like they had their territory. After a week or two, I took the fence out, and all seemed well.
I will add that silkies will not always sleep under the roost. In fact, mine almost never do. However, once they pick a spot, they are very stubborn. Their spot will occasionally move around, but they will never sleep where you want them to. I had one hen that insisted in sleeping right underneath the roost, making for a gross mess of her feathers in the morning. I tried to move her, but she refused. After a week or two, she went back to sleeping with the rest of the silkies. They don't like getting pooped on either, and it doesn't take long for them to figure it out. Good luck!