Not sure about the origin of the real one, but those plasic or copper toilet tubes seem to be the same diameter (and only cost a buck or two). I glued mine on as well, but I think I ran two small screws (from the inside of the gauntlet outward) in there as well in the event one of my hoses got caught up on something (wouldn't want to rip it off of there).
I believe it is 3/8" tubing. I went to Home Depot and found mine. It's Copper, and it is in the section where the toilet tank kits and stuff is. It is the water line that goes from the spicket coming out of the wall, to the toilet tank. It has like a mushroom shape on one end. Then I cut it to size and Glued it on with lots of JB weld. you can see mine attached at: http://photos.yahoo.com/roberteidemiller
Click the folder titled hose connecters.
Hope this helps.
I bought a brass tube from Hobby Lobby Also, but liked the thickness of the copper better. Just personal preference. If I remember correctly, the copper tube was under $2.
Either way, including plastic, would work. I bought a plastic tube also, but was concerned with it breaking if my hose caught on anything. I thought about using velcro to attach my tubes under my short sleeve so it would come off at that connection instead of at the Gauntlet.
Also, roughen up the area of the tube to be glued just to make sure it has something to grab(the Glue).
I'll shut up now