Four monitors with a single GPU, with some "special requirements"

At the moment I have the following setup: Two GTX 560 TI with three monitors and one projector connected to them.

With some tweaking of xorg.conf (TwinView + Xinerama) and some minor code changes to Xinerama.c (basically just adding number of devices and individual resolutions) I am able to achieve the following desired setup:

  • 3 monitors run a 1600x1200 resolution each, the projector runs 1080p
  • openGL hardware acceleration across all monitors and the projector
  • windows can be dragged around all devices (e.g. a text editor opened on any monitor can be dragged to the projector and vice versa)
  • when a window is maximized it is maximized to the monitor / projector it is on (it will not extend over two or more devices)
  • Linux “sees” four screens, i.e. XFCE can assign a different wallpaper to each device

My question now is: Can I achieve a setup like this with a single nvidia GPU? If yes, which one would you recommend?