Which driver, if any, support 4 dual head independent display

[Donald Kayser]

I am involved in the planning of a device and it would be best if it  
could have 4 dual-head graphics PCI devices with independent data on  
each display. Does anyone know if, 1) there is enough address space in  
32 bit kernel for 4 PCI graphics cards 2) Any drivers that currently  
handle such a configuration?

Any comments would be helpful.

Donald Kayser
xorg at kayser dot net