I'm in the hunt as well... word has it that Kentrol makes the best tube and associated parts (www.kentrolinc.com). Malotte is also in the business (www.malotmfg.com). I'm going to ask around some more, but I have it on good authority that the Kentrol setup is smoother (you can use your tailgate with Kentrol... Malotte has integrated tailgate that doesn't drop). It all depends on what you're looking for.
Anyone out there had experience with either outfit, or knowledge of other manufacturers?
Kentrol is the only one that I was aware of. Personaly I don't own an eb, but my friend has two. One is real with steel, and the other has a glass tub from Kentrol. Real nice, though I am with the first, as I mentioned before steel is real!!!