I think it really does'nt matter if the other dog you are getting is a puppy they learn as they grow.
I have Cheyanne 4yrs and i thought the only way to go was a male i got Aspen and then came along Phoenix i thought i might have a problem with the 2 males but they LOVE eachother there always together and Cheyanne jumps in when she feels like it .

good luck i know there all so cute+ cuddly you just want to take all of them home