OK, here we go

Processor : Intel Computers - Core 2 Duo E6850 Dual Core Processor - BX80557E6850

Motherboard : GigaByte Computers - GA-P35C-DS3R Motherboard - GAP35CDS3R

Memory : Corsair Computers - XMS2 2GB PC2-6400 DDR2 DIMM Dual Channel Memory Kit - TWIN2X20486400

Videocard : eVGA Computers - GeForce 8800 GTS Video Card - 640P2N821AR

HDD : WD Computers - Caviar SE16 500GB Hard Drive - WD5000KS

DVD : Lite-On Computers - LH-20A1H Dual Layer DVD&#177RW Writer - LH20A1H186

Case : Antec Computers - 900 Midtower Computer Case - NINEHUNDRED

Power Supply : OCZ Technology Computers - GameXStream 700W Power Supply - OCZ700GXSSLI

Webcam : Logitech Computers - QuickCam Fusion Webcam - 9614030403

I suggested a very good case for you better than the one you chose, it's up to you to choose between them.

The motherboard has integrated sound, it's quite good, so you shouldn't need a sound card.

These are quality parts, trust me you should build an awesome PC with them !