
I know that you have done it before, but that was some years ago, two pups together really are double trouble, and most breeders will not knowingly seel into this set up. Why not contact Rescue for a nice bitch of around 5 years old, and after she has settled and her training is to your liking then consider getting a Puppy to join her.
You then have the advantage of the pup accepting her as being higher in the hierachy, she can be a good example, and company, and you can concentrate on training and bringing up the puppy.