Couldn't you just go straight to the BD site? That's the brand I've always gotten from pharmacies.
In person, any major chain pharmacy in the u.s. should be able to sell you needles. There are a lot of addicts around the pharmacy I use, so I do have to explain to them that I am trans or they refuse to sell me anything other than prepackaged diabetic kits. I've gotten them at a Fred Meyer further from the city center, and they didn't ask any questions but they had difficulty figuring out how to ring them up and charge for them.
That said, I get mine from Stroheckers. I only go to other places if they give me the wrong amount or if I want to change sizes or something. On my most recent visit they gave me some needles that slip on instead of screwing on, and I'm disliking that enough that I plan to use up the leftover screwy ones and then buy more somewhere else. I'll try to remember to check in if I do it online.