Everything is slotted. There should be no soldering. Check www.pricewatch.com. Still pretty much the best place to look for the best price on stuff. If your looking to get it all at one place try www.newegg.com . Never had a problem with them. If you want REAL top of the line expansion, make sure you get a motherboard that has 2 PCI-Express 16 slots for Dual SLI. Don't worry too much about sound unless you intend to do Pro sound work too, the built in sound car will probably be good enough. I only recomend nVidia graphic cards because ATI's Linux drivers suck. You should at least leave yourself the option of running Linux. Anything in the Geforce 8600 line is going to be just fine. Honestly, I don't think there is a single 3D program that can fully use the graphic capabilities of most 3D cards. 3D Modelers and renderers are almost a decade behind the latest games in implementing the new technology. Unless your looking to get the bleeding edge out of first person shooters like Half Life2, Unreal 2007, or Crysis, you won't need more than that. For drives, go SATA. 500GB is the current best price point. To figure out the best deal divide the price of the drive by the number of GB and get the best price per GB. If you want run MacOS X86, go for a motherboard with a recent Intel Chipset.

mo·nop·o·ly  [muh-nop-uh-lee]
noun, plural mo·nop·o·lies.
1. exclusive control of a commodity or service in a particular market,
or a control that makes possible the manipulation of prices