I like Hunter as a backup center, but he's already 27, will need time to get back in the flow of things with his injuries, and at this stage of his career is probably best served as a 3rd string center for some aspiring playoff team.
Swift is young and has shown very small signs of being a potential rebounding/shotblocking type player in the NBA, and while he had some offensive skills back in HS, he's proven to be more reliant on athleticism in the NBA, so the injury problems he's sustained doesn't exactly bode well for him. He'll get a chance (Boston), but I don't think he'll reach his upside at all.
Foyle is one of the nicest guys in the league, was a great shotblocker back in the day, but is just getting old. Past the age of players we really should covet, even if we need that shotblocking (that shotblocking needs to come with young legs).