As far as I know Parallels Workstation can be started on one monitor in fullscreen mode and one can work simultaniously with primary OS on another monitor. But better download trial version and check it yourself.
I work here wirth a dual mode configuration with a laptop and an external monitor. I could start the parallels Vm on one monitor as every other X app. But when I switch to fullscreen mode it's not possible just to point the mouse from one monitor to the other. The mouse won't be released. I have to switch to the "normal" window mode, then I could move the mouse from one monitor to the other, work there, switch back. fullscreen again, ... The answer is: Yes, with restrictions in fullscreen mode.
How do you enable full screen mode and occupy only 1 monitor? When I enable mine it occupies both monitors. I was able to change the resolution inside the guess OS (WinXP) to fit almost 1 monitor. TC
Ah, sorry, I forgot to write that I don't use Xinerama because I have to different resolution (1400x1200 and 1280x1024) and Xinerama behave very strange. I have a simple dual head config with two X Servers. sorry for that!
