So a selection list would work perfectly for what I'm trying to do (thinking of creating my own AceGUI widget for it so I can use it in my AceGUI styled settings eventually but for now outside of AceGUI).
Anybody done or seen this done before in a wow addon? It's not something I couldn't write but don't want to be reinventing the wheel if I don't have to so thought I'd ask. I don't care about the "submit" button or the label at the top in that link btw. I just want the two scroll frames where you can select multiple items at once from each (and they lock highlight when selected) and the two buttons in the middle.