I personally like yorkie's better than silkies. Of course, I only own yorkies so I'm probably a little partial. I just don't think you can beat their looks or tempermant

Of course I have seen some silkies that look like yorkies and vice versa. I think you just have to decide what you are looking for and go with that. You can get a yorkie up to 7 pounds and still be within the standard, but if you were looking for a bigger dog and wanted to show it, you might be better off with a silkie. If you don't plan to show than whether or not you get one that's within the standard is entirely up to you. As to their coats, the only expierence I've had with them is the one a friend of mine had and it's coat is quote short. Just a little below its belly and won't grow any longer than that...
Let us know what you decide