Do you need your columns to be resizable with a StretchableLayoutResizerBar? If not, I don't really recommend using that class, it's a complicated beastie that was designed for a particular purpose. If you just want to lay out a bunch of components, I've always found the easiest way is just to do the maths manually.
(However, I am interested in the new HTML flexbox stuff - that seems like it might be worth copying now that a lot of smart people seem to have finally agreed on it being the best way to structure box-style layouts)