if you didn't solved your problem yet, first of all, use the HWiNFO32.
This will give you precise info about motherboard model, number etc.
I think, that you have the one with Uniwill KA/KA255 series.
Well, go to the Uniwill laptops website. A small advice:
they have BETTER manuals, BETTER drivers etc then FSC
, I'm working with my A7640 with Uniwill's set.
About graphics itself: it's SiS 760 graphic chip, integrated with MB. There is no free/usable slot for another graphics installation inside.
If integrated graphics is not enough for you - I have the bad message - you have to buy another laptop.