I have a Brother machine and its called a Re-positional hoop. I am sure if you google 'Hoops for--------' then put in your machine, it should come up with all the hoops available for your machine.
Check out Allstitch..
You might try looking for "endless" embroidery hoops. I have a Viking and that is what they call their hoop that works similar to what you describe. Friends with a Berninia have something similar.
I bought the hoop it all years ago from Sewforless site. I wasn;t able to get the long one just the double wide. At the time I saw one at a craft show here in Australia for a cost of $399 just for the hoop and bought it on line for $69 USA with the support table included. Cost me about $50 in postage but still a big saving. Worth looking at their site.
If you go to Amazon.com and search for embroidery hoops for your brand of machine you may find something that will fill your needs.
Are you talking about hoop it all?? These dont fit any machine but are available for all brands and various models of embroidery machines!
Check it at....
http://www.hoopitall.com/hoops/