Hi Snuggles2013,
I think that any of the heavy duty bedframes made by the better steel frame manufacturers would work well (see post #10 here) particularly if they use thicker angle iron (more than 1.5"). I think the glideaway K43 you linked (which will support the weight of a waterbed) along with the Mantua Craftlock you linked and their Sealy bedframe here, and the Monster bedframe here are among the strongest. The Knickerbocker Embrace is stronger yet but is in a much more premium price range that is more about designer aesthetics than strength.
Phoenix