You can also try your local homebrew store, or order them from Penzy's (http://www.penzeys.com/) - much cheaper than Whole Paycheck! (Penzey's is an outstanding source of spices.) Also an alternative to saltpeter is Morton's Tender Quick Cure (http://www.mortonsalt.com/for-your-...g-and-pickling-salts/178/morton-tender-quick/), which I can pick up at most any grocery hereabouts.
And that is one fine chunk o' corned beef! Makes me hungry looking at it.
I figured Penzey's would have them, but I do not plan on making this very often. I was told that my corned beef takes up too much space in the refrigerator