No, unfortunately. I haven't really searched much. My patience for trying out new tools isn't all that high. The only two I've really used have been NetNewsWire (which I stopped using I think back around the time NewsGator acquired it) and Prismatic, which I never really found useful. The closest thing I use now is HN. I think likely the next tool I'll use in this space is roll-my-own as the author has or some app that provides the building blocks or plugin architecture for customization along those lines.