I always like to see our pups have company of their own kind if people can swing it. Mine have so much fun with each other. They play and attack and tease. They are like children playing with toys. I get so much enjoyment just watching them interact, maybe even more than when I am the one playing with them.
I think it would be nice to make your pick of the breeder you want, and then bring along Belle when it comes to picking the exact one. But if she does not instantly take to one, I would not let that deter me. Mine usually cold shoulder the newbie for a week to a month before they are fully accepted. My little Annie was VERY persistent and just kept after them til they had to play with her by defeat.
So she broke previous records and had them bonded within a week or so!
Sorry for your losses -- I lost two of my pups in the same year too, so I can empathize with you -- one a 17 1/2 year old dachshund and the other a 4 year old Yorkie. I had a bit of hard time handling it and even took an extended break from YT as I had a hard time even talking about it. But I finally got to a place where I could feel right getting another -- actually for me it was not planned. My breeder friend called saying she had the exact female puppy I had always described wanting -- sure enough she did -- my Annie!