Are you nuts for that price I would build my own, screw the custom case. The series seems to range from a single 6800GT to SLI 7900GTX, which level are buying?
If you know enough about gaming rigs to be spec this macheen, why not just spec out your own rig and build it yourself? It took me a few days to read the reviews of SLI mobos, AMD 64 vs. P4, P4D..etc.. what level of graphics card I could afford. Then a little about DDR ram, now you have the choice of DDR2 for system ram (recommend DDR2).
Place your order on-line, (throw in a cool looking case, Zalman CPU HSF, OZC PSU) and in a few days your stuff arrives.
In a few hours on a Saturday morning it was all installed including Windows and by noon I was loading HL2 and gaming.
It was a great experience, you learn so much about the latest hardware and you learn how to build your own. The mobo instructions are easy to follow. The whole thing is just a great way to get to know PCs.
Food for thought.
Peace.