My recommendation? If Cash seems "lost" and has confidence issues, he may do better with an adult dog whose behavior is a good model for him -- I'm thinking firmly in charge, but friendly. All RR Rescues have dogs right now, so there's bound to be one out there that would be a good pal for Cash. Or, you could start networking with RRCUS breeders in your area to see if there are any adult return-to-breeder dogs that are in need of a loving home.
If you're set on a puppy, then I'd go to a very reputable breeder and let her/him know what personality Cash needs. IMO, a confident, outgoing, "bossy" puppy from a well-bred, temperament-appropriate litter would possibly be a better selection than one that is more likely to mimic Cash's behavior quirks. That is definitely a topic to bring up with the breeder. A breeder with good experience will be able to help guide your puppy selection.
Be prepared to wait a bit, however, for a responsibly-bred puppy and in the meantime, work to re-establish a structure that helps Cash adjust to not having Bobbie Jo there to model for him what to do and how to act.
Keep us posted on what you decide and how it goes. Your situation is one many of us (myself included) may face at some point.
Litter announcements / solicitations are by approval of the Administrator/CoAdministrator- only.