Are you talking about the screw terminal strips being rated for 20 amps? I would think that would be 20 amps per circuit. I *think* you're talking about jumpering one side together to form a common bus, right? If so, that 20 amp rating doesn't really apply since that's per circuit. So you'd need to figure out a way for the jumpers to carry a heavier load. Or am I totally off base here and you're not talking about what I described above? Some electronics shops even sell metal jumpers that you can create a common bus with. And they do make a single bus screw terminal like the one you have pictured, they're just kind of hard to come by, I don't even remember where it was that I saw them.