http://www.eztube.com/
this is the one i was thinking about ordering from. they will actually cut the tubes also to your sizes if you give them measurements which will save on shipping 8ft tubes. i don't think they guarentee the fitment on to standard tubes as they might be different. but i am sure that you can check the tubes you get locally before buying the connectors.
they sell to small people like us... not sure if there are other sources... but this is the one i was thinking about ordering from...