I run Poser Pro 2012 with two monitors. The only panels that remain on the monitor with the preview window are the one's I CAN'T move ;). Just be advised you'll have to the panels on each room tab individiually, and the floating dock will stay the same size and in the same place between tabs. Set up the library panel first. Then place the other panels around it.

edit: my monitors can't do the resolution you're referring to, so I can't tell you anything about that ;). You can expand the preview window across both monitors, but then you have the problem of covering up your other panels ;).

Laurie