If your willing to spend a bit more, the Acer Ferrari 4000 has a DVI-D port and supports dual screens (laptop screen and standalone). It is powered by an ATI Radeon X700 PCI-E chip with 128MB dedicated RAM. Its worth checking out, priced at about $2200. Mine is on the way, so i'll post some more when it gets here!
Besides... I also found this, which looks like it may be a better deal $/feature wise... I am just hoping that this isn't the only, or one of two, laptops that offer this... I mean why so few Athlon 64 laptops, and why does almost no one use DVI? It just doesn't make sense.