There's not too many places to buy detailing products around Boston except on-line. Look in the yellow pages for a "paint & body shop supply" store. They usually carry professional versions of products from
Meguiar's and 3M and also some lesser known brands.
If you're ordering on-line there are a number of places located in New York like Detailer's Domain and Detailed Image. Ordering from a place in NY will get you your goods overnight for the price of ground shipping. Ordering from places in Florida like Autogeek will entail a 4 day or more wait.