well for some of them.. if cost really is not an issue
processor- Intel Core 2 Duo QX6800 (QX6700 is much easier to get though)
Graphics card- Nvidia Geforce 8800GTX (two of them in SLI if you have the money)
Physics card- even if you had infinite money, it would be pointless, utter waste of money
soundcard- Creative X-Fi series, any will do really
motherboard- something based upon an Intel P35 chipset or Nvidia 680 (i think)
hope that helps.. most of the above are not cheap though!! You can get probably get most of the performance for half the price if you look around wisely. The absolute top stuff is often not proportionally worth the price in terms of peformance.