First off~~~~Welcome to YT
I had never seen a Silky Terrier prior to attending a dog show last year. My only Yorkie is a big girl at about 11 lbs and I have had people stop me and insist she was a Silky just because of her size. After see many Silky's at the show I can tell you that a Yorkie and Silky look totally different. Their body are proportions differently, their heads have a different shape and they really do not look anything alike when they are Show quality. BUT then you also have to understand that how a Yorkie will look as an adult also depends upon who your breeder is and if they are breeding to standard. Just because you purchase a Yorkie does not necessarily mean you are going to end up with your idea of what she will look like as an adult. Make sure you do a lot of homework and research on your breeder prior to making your decision. Owning a Yorkie is a very long commitment that should be taken very seriously.
Here is a very good checklist of what to include in your search. Good luck!
http://www.yorkietalk.com/forums/yor...ead-first.html