I'm not going to pretend to know for certain, but I do not believe that NY residents are allowed to purchase restricted firearms out of state. I think, in fact, that it's legal for you to buy them in the other states, but you're not allowed to bring them into NY, nor own them there.
There are a few other guys on here that can weigh in, and you might post this in the Guns section to get a little more visibility, but I'm fairly certain that was the last status I had heard for unfortunate new yorkers.