I think there is no wrong or bad choice here. This dog is lucky to have 2 good options and you should be very happy about that!!

You are being considerate thinking of your mom when you go away. I'm glad Rachel mentioned it first - the dog would be small enough for a plane! But - do they charge more to bring the dog on and can you afford it? What about when you're in NY - you need to concentrate on the class.

I do believe another Yorkie will come along just as sweet, the fact that you would hesitate at all indicates that now is probably not the best time.