Were you at a regular grocery store?  Grade B maple syrup will most likely not be found at a regular grocery.  You'll need to go to a health food store, or Whole Foods, or order it online.  I get mine online here:  http://www.myvitanet.com.  This place usually has it the cheapest, but I always do a web search and shop around first to make sure I'm getting the best deal.  Also, if your order is $100 or more, you can get free shipping.  I usually just stock up on syrup and tea (they have Smooth Move tea too)! :) 

The health food store is also going to be your best bet on finding senna tea.  I live in Ohio and have found the tea at Meijer (with the other teas) and Kroger (in the natural foods section) as well.  So it can be found in regular grocery stores, but you may have more options at the health food store.

Grade B and C maple syrups have more mineral content than Grade A.  They are usually darker.  Since the syrup is going to be one of your main sources of nutrition, you want to make sure you get the most nutrient dense. 

Also, make sure you have a good brand of sea salt.  Himalyan, Celtic, or Redmond's are all brands that I have seen people have success with on this forum.  If you just buy any old sea salt from the grocery, you may not have as good of results with the salt water flush.  And I've also heard that the taste is much better with the brands mentioned above.

Good luck on finding the ingredients!

Tiffany