FWIW my favorite long clamps are the Dubuque aluminum channel ones. Lee Richmond (thebestthings.com) has good prices on
sets of 4 and 10, drop-shipped from the factory. The HF clones are about half the price, but I've had marginal experiences with their stuff and am willing to pay double for the US-made Dubuques. They're almost completely replaced pipe clamps and steel bar clamps in my collection due to the huge weight difference. I keep heads, pipes, and couplings on hand for when I need very long clamps, though.
For stuff that requires more depth I use a combination of Bessey Revos and long F-clamps (mostly Bessey Tradesman and the "heavy duty" ones from LV). Be aware that the Besseys have been discontinued and that an improved design is coming out shortly, though.