I'm mostly using 1" tape these days so I have some nice stock on eBay (local pickup available in Montreal).
Quantegy 456 1/2" pancakes NOS:
www.ebay.ca/itm/?
Quantegy 1/2" empty metal take-up reels:
http://www.ebay.ca/itm/?
BASF German-made NOS SM911 1/2" tape
http://www.ebay.ca/itm/?
3M 996 NOS 1/4" reel with matching take-up reel:
http://www.ebay.ca/itm/?