Hi Golden Peace, welcome to the hot pepper discussion forum. Please pop into the Welcome thread and introduce yourself when you get a chance.
As for the peppers you seek. Unfortunately, you are currently in the off-season. You are not going to find any Dorset Nagas in New York City, unless you can get your hands on a jar of Mr. Naga Chilli Sauce. That said, the Dorsets will be available in the early fall, but the Michauds will only deliver to UK addresses. Don't hold your breath on seeing any Dorset Nagas any time soon.
The Red Savina is much easier to get. Simply contact Jim Campbell at Mild to Wild. I doubt he has any fresh Red Savina at this time of the year though, but you should be able to get mash. He will have fresh peppers at the end of the season, when the peppers have ripened, but I don't know that he will sell them fresh, and if he does, I think you need to be ordering a pretty decent quantity in order to get them from him. He isn't the only certified RS grower I know, but he is the first one I would go to.
By the same token, you can always get the seeds and grow your own, that might be easier.
T