I would proceed cautiously. My older Yorkie, Vinnie, has been known to be somewhat dog aggressive/dominant/territorial. When I decided to adopt a second Yorkie, I worked with a rescue group in our area (
Rescue Me Yorkie Rescue), as I am a big fan of adopting dogs that are really in need of homes. The people who run the rescue were awesome. I told them about Vinnie, his history, and what we were looking for with regard to a new dog. We did a "meet and greet" on neutral turf before finalizing the adoption, just to make sure it would all work out. Definitely check them out.
Another thing to consider is cost. Two dogs equals twice the cost. I don't know what your financial situation is, but it is just something to consider. I really made sure I was financially ready to provide care to 2 yorkies before proceeding with getting the second.