I found this link to a card:
MPCI-VGA
Mini-PCI Module
Volari Z9M GPU
on Mouser (but I cannot find a price, it says 'restricted availability')
MPCI-C-VGA LiPPERT By ADLINK | Mouser
The data sheet says LVDS Interface (Optional LVDS requires a BIOS change.)
VGA up to 1600 x 1200 x 16, LVDS up to 1600 x 1200, 18 bit display support, Drivers for Windows, Linux
The data sheet link http://www.mouser.com/catalog/specsheets/MPCI-VGA.pdf
I am not very experienced in this area, so I don't know if this card is compatible, if anyone gets any further, please let me know. Obviously we all need to find a well priced card, with a suitable display, and decent drivers.
---------------------------------------
EDIT: Looks like I got this wrong (the card I linked to is a Mini-PCI, and not a Mini-PCIe).
So it looks like we need a card of the size of the middle card (in the image above).
Damn!