Here's one I built a little bit ago (project indefinitely on hold, but the stand is ~90% done (need to do another seal coat, and finish up some details on the inside)).
Almost all 2x4s and 2x3s, and really overbuilt. I'm fully confident it could hold several 40B's worth of weight. Just used a circular saw and drill for the assembly (and a pockethole kit, but if I planned the assembly better, I could have done without it), and a propane torch and nylon scrub brush for the finish. The tank sits down inside it, and that outer bit covers the foam, frame, and maybe bottom 1" or so of substrate. Also has about a 5-6" shelf in back, so I can support whatever.
If you don't have tools, you can get wood cut at most places, it's just not always a terribly accurate cut (depends on the place/person/etc.). If need be, you can even cut 2x4s with a cheap hand saw, it just takes a lot more effort. I'd be loathe to do the assembly without a power drill, even though I built a couple stands in college just using a hand saw and leatherman. :/