I've always had to buy off the interweb. Not a bad deal, no tax and arrives at your door.
These rotopax are easy to find but not easy to get a 'good' price on. 99% of the time they are full retail.
Scepter fuel cans awesome but kinda hard to find. I got some a few years ago from the black market out of Canada and a few more a few days ago from 'gray' market out of California. Not sure how he got them and don't want to ask. The scepter water cans are easy to find and cheap.
What are you looking for and we can help you look....