basically anything with a small memory footprint, because you want that for the game
Also, you'll
probably[1] have to forgo adding the fglrx and nvidia drivers to the CD/DVD unless you can get permission from AMD* and nVidia** to do so.
*If AMD keeps their word and opens their drivers the fglrx driver may not be an issue.
**
2.1.1 Rights. Customer may install and use one copy of the SOFTWARE
on a single computer, and except for making one back-up copy of
the Software, may not otherwise copy the SOFTWARE.
That pretty much forgoes redistributing the nvidia kernel driver without their permission, there is the nv driver which doesn't require that, but anyone with a 6100 and up (IIRC) will be SOL as X will not display properly, the nouveau driver doesn't support 3D yet.
[1] Granted if you host the CD/DVD in Cuba, Venezuela, China, or Singapore (or any country that doesn't give a rat's ass about US laws) you might be able to get away with it.