To respond to the original post ...
Taking on something like this and hoping to get a good and usable result depends at least on what tools you have, your skill in using them, and your abilities and experience in this kind of project. The stand in the posting you link to (though little of it is showing) shows evidence of being produced by a woodworker who knows what he's doing and has the tools to do it. For example, it shows definite evidence of being fabricated via use of at least a band saw, a router (more likely a router table), and maybe a lathe -- not to mention a drill or (more likely) drill press. Could you do it with hand tools or hand-held power tools? Sure -- if you have the experience and skills and tools. How much would it cost you and how much time would it cost you? Probably a lot. I could probably knock off that stand in an hour or so (once I had the design down well), but I've got all the tools to do it. If you don't, then I'd advise not going in that direction.
Metal stand? Got a welder, grinder, appropriate saws, metal lathe? Same story. My son and I are making a custom tailgate for a 1-ton pickup. It's a simple project and is taking quite a bit of time because of our inexperience. Would almost certainly have been cheaper to buy one, but it's for his sister-in-law and will be truly custom.
If you decide to make a stand, will you make it for a single tuba, or will you make it adjustable for others as well? That gets more complicated. A few years ago I developed a really nice design for a (adjustable, laminated bent wood) euphonium stand, but haven't had a chance to get to it. However, even the prototype will be a bit costly since it's a first-time thing.
My advice is spend what it takes to get a decent commercial metal folding stand. The price range is pretty wide. I can tell you that for a number of years I've used a Jupiter stand:
http://www.amazon.com/Jupiter-TE70-Tuba ... B0002F761O. I got it because it seemed virtually identical to the K&M stand, but much cheaper. I think I paid $70 for it. You almost certainly won't be able to build one for that money once you add up materials and tools costs. I've used it with a Cerveny 781 BBb, my Wessex EEb (981 clone), and my Buescher 1924 Eb tuba. Works great. No problems. I can't imagine what more a "better" steel folding tuba stand would contribute.