Case - if that's the one you like.
Video card: I'd be a lot more comfortable with an Asus instead of the Novatech house brand.
Ram - 1600 isn't necessary, but it's the same price as 1333. It will work.
Power supply: Absolutely not - stick with known high quality name brands.
Corsair TX 650W ATX2.2 SLI Compliant Power Supply
CPU/motherboard: Good. The CPU comes with a cooler.
Hard drive: No.
Western Digital Caviar Black 500GB 32MB Cache Hard Disk Drive SATA 6 Gb/s 126MB/s <4.2ms 7200rpm - OEM
OS: Good. You can't reuse the Dell XP.
If your optical isn't SATA with a standard front bezel, get this:
LiteOn IHAS124-19 24x DVD+/-RW SATA Black - OEM