Autodesk now handles multiple cores well and is a fairly open platform.
If money were not option I'd buy a 2P workstation and put two Zeons or Opterons in it with 32Gb of RAM and a couple of workstation graphics cards.
That said a decent quad core system (overclocked i7-920 to 3.5) with a 5850 or 5870 ATI card and two 1Gb HDD's (shortstroked) or 2 SSD's in RAID0, with a couple of 1Gb drives for storage, and 12Gb of RAM would be a lot cheaper and do the job well.
Have a 750W PSU instakked and a quality case with two 120mm fans to keep the innards cool.
You might need a tecky to put together the above ... but it will work fine ... with a decent aftermarket heatpipe cooler (where you live it gets hot in Summer).
Cheers.