The short answer to you question is "No." There is not a club that I can think of that has a significant reputation for being a keeper factory. There are very well known keeper trainers who are employed by certain clubs, but they often bounce around, so it's not easy to steer you to a particular club.
Good description above from Dargle about the way a club ought to handle the keepers. But I do have to agree with MDAK, most have no clue what they are doing, at least from an organizational perspective. It's all about the individual coaches and GK trainers, not about the clubs... and remember that as long as your kid plays. It holds true for almost any question you have about club soccer, not just this one.
You basically have to locate the individual head coach and an individual keeper trainer who know what they are doing and are a good fit for your kid. We had success when we scouted coaches from local clubs who had played the position in college (rare, but you do find them...just look up their names on Google or read their bios on the club websites). If you get a head coach who played keeper, you're going to have a much better time. But since that is rare, at the very least you need to find a club that has weekly age-segregated keeper training, like Dargle said. Depending on how much you're able to spend, if the club keeper training sucks, or if the club of your choice doesn't have dedicated keeper training, you will need to find a private GK trainer. At the older levels, my kid does team practices, plus the club GK training, plus private group sessions with her own trainer every week during the season. We also supplement that with one on one sessions with her trainer as needed. It will get pricey. But at your son's age, you should be fine with once a week club keeper training, as long as it is good quality.