Ah. I had accounts with a couple of multi line distributors that I could get Shimano hubs (and other Shimano stuff) from, but some of them did not carry all models. I also had an account directly with Shimano so I could source anything I couldn't get elsewhere.
Any reputable LBS that pays their bills can do this.
That was usually the second choice though, because while the distributors could have the product in your hands the next day, direct from Shimano could take a couple of weeks, and the price was about the same.