Congrats!! I think the two breeds should go together well! Do tell us more about them. Did you intend to get a Chi when you got your yorkie? Just wondered if it was planned or could you just not resist getting another? (How well I understand that feeling!) They can grow up together now and I'm sure your yorkie will soon get used to the little Chi!!
Regarding a name, what is your Yorkie called? A name that goes together well might be an idea, maybe starting with the same letter etc? Sorry I can't help more than that but I'm sure also that a name will soon come to you as you watch them play!! I'm getting a pup too in 3 weeks so would love to hear more details LOL.
Ana xx