Welcome! Sorry to hear about your loss.
I know the people and the dogs you are talking about; Paco was in the spayed female's last litter, and the 1 and a half year old female is his littermate, who I see on a regular basis because I tutor her owner's nephew. The black and white male Basenji you met is Paco's sire.
There are no puppies or upcoming litters that I know of, and there aren't a lot of purebred Basenji's here in the VI. The one and a half year old female desperately needs a good home, as her owner is tired of her escaping, and the breeder (the man you met) won't take her back. He is looking for an owner, but she desperately needs training, and someone who understand Basenjis. Any stimulation leads to biting, and the neighborhood children are all scared of her.
I suspect the Basenji's in the shelters on St. Croix and St. Thomas are all from former (or the most recent) litter of the dam who the man you met finally spayed last year after being unable to find homes for nearly an entire litter (the one I described in this thread; Paco's litter). I know for sure that two were sent to St. Croix free of charge when he couldn't find anyone to buy them. I don't know what happened to the two other pups that were in the litter; I have to hope they found good homes on St. Thomas.
I would recommend seeing if you can talk with breeders or BRAT about looking for basenjis in the states if you really, really want a purebred Basenji pup, and transporting the pup here. Personally, I will probably be at the Humane Society of St. Thomas when I'm ready to add another canine to the family.
edit: I just noticed that you are also looking to help the spayed female and the 1 1/2 female tri: There is a woman who works at Bella Blue in Yacht Haven who is interested in the 1 1/2 year old tri, but I gave her information to the tri's owner and I don't know if he ever contacted her. I had no idea that the spayed female needed a home as well, but she seems better tempered and trained, or did when I met her to pick up Paco.