Registered ram is recommended, but some unregistered works as long as you are only using 1 stick. If you want to use 2 sticks, registered is an absolute must (same with Pegasos).
A list of known working ram modules is being put together by the developers.
I think we can expect the Voodoo to work as there are exisiting PCI drivers to start from and it would be almost suicide to not have support for them. Other cards (radeon etc) may follow in updates, especially 3D drivers. Really, any VGA/SVGA/XVGA compliant card should work in 'normal' modes.
As for Hard Drive space, I don't think youll get close to using up those 2x6Gb in a hurry!
