Since nobody else mentioned it: Directory Opus. Looks big and clunky at first look but it's actually very fast and 100% customizable. You could strip it down to a dual list view and operate it purely by keyboard shortcuts. Buttons are defined in a copy pasteable xml format, are scriptable, come in various forms and let you bind events for left/right/middle click. The only caveat is: windows only. I would kill for a Linux version.
My brother! Seriously though, Directory Opus is a magnificent tool. Its interface could use a lot of work, but its extensibility isn't matched by anything in the Linux world. I know, I've looked and looked. I couldn't even find a decent open source project I could dive into with the goal of making it as flexible as DOpus. I emailed the DOpus guys and they definitely won't create a Linux port. And as I'm sure you already know, it doesn't play well with Wine. If I were creating a comparable application for Linux I'd make it extensible via Python rather than the custom scripting language they use, and I'd take a good long look at things like Sublime Text for UI cues (how to present a massively customizable and extensible system and maintain a very 'clean' interface). It would be a big project, but if I had the time I would gladly sink those hours into such a thing if only so I could use it at the end...
Path finder on OSX comes close. DO on the Amiga circa 1992 is still superior with the commands down the middle, kinda like Midnight Commander but better.
