The best thing to do is when you get to your hotel open the phone book (The one with yellow pages), look under "hobby" and then call the shops to see if they carry what you are looking for. There are allot of small shops here too so don't expect to much from them.

I do allot of traveling and this is the method I use when I get to a new town. Heck, I'm writing this from a hotel so that should tell you something.
Best of luck and welcome to the USA.