the best bday present you could get would be another yorkie
haha...just kidding
not really but sorta kidding LOL
whatever you do (or have done...I didn't read all the posts yet), I am sure that it will be tons of fun and very memorable. I think having a play date is a dogs favorite bday present (my dogs anyway) having other doggies to play with is always a lot of fun.
good luck!!! I'm sure you will have a blast.