For graphic cards, you will need a pci expansion board such as mediator pci and it's limited to pci video cards, no agp. The voodoo works very well on the mediator(pci voodoo) and allow you to play 3d accelerated games, but you can't have it on the a1200 case, you will need to towerize it.
For the hd issue, you can use sfs wich is a better file system and not have the 4gb limit on partitions, as well as a more secure file system.
