I have a Yorkie Maltese Mix. He is wonderful. He is bigger than 5 lbs though. He was a breeze to potty train and is just the most wonderfulest little dog ever
He looks mostly yorkie, just has curly hair on top of his head. His parents were 5 and 6 lbs, but he is 8 lbs, so I don't think you can ever know exactly how big they are going to be. I only have the one, can't help you on the having two question
I have thought about getting another myself, just not sure I want to mess with a good thing
Here is a pic of Cooper as a baby and more recently.