$800 gaming system, looking for suggestions

Hello, i'm trying to finish my PC and have it ordered within the next 2-3 days. I have decided to revise my original post. My first thread was about upgrading my pc using some old parts. But I have found a buyer for my old PC and this has given me another $300 spending limit, bringing my new budget to $800.

So I can use some advice on how to round out my system to get the best bang for the buck. I will be using this pc mainly for gaming. Mostly for WoW, from what I have read, it is mostly a CPU consumer over GPU. Eventually I would like to OC mildly in the future. Mainly means that i'm trying to skip out on the third party cooling for now if I can't fit it into my budget. I also need an OS included in the system, i'm unsure if I should go for the 64 bit Vista.

Parts list so far:
http://www.newegg.com/Product/Prod [...] 6819115037
Intel Core 2 Duo E8400 Wolfdale 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor

http://www.newegg.com/Product/Prod [...] 6813128359
GIGABYTE GA-EP45-UD3R LGA 775 Intel P45 ATX Intel Motherboard

http://www.newegg.com/Product/Prod [...] 6814102770
SAPPHIRE 100245L Radeon HD 4850 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready

http://www.newegg.com/Product/Prod [...] 6820231122
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory

http://www.newegg.com/Product/Prod [...] 6822136218 (Changed)
Western Digital Caviar SE16 WD6400AAKS 640GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM

http://www.newegg.com/Product/Prod [...] 6817171023 (Changed)
COOLER MASTER Real Power Pro RS-650-ACAA-A1 650W

http://www.newegg.com/Product/Prod [...] 6835186134 (Removed)
ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler - Retail

http://www.newegg.com/Product/Prod [...] 6811146025 (Changed)
NZXT Apollo Black SECC Steel Chassis ATX Mid Tower Computer Case

Total: $743.92 / $693.92 after Rebates Which leaves $100 for the OS

This is the monitor that I will be using.
http://www.tigerdirect.com/applica [...] u=H94-1900

Eh I know I said I didn't want third party cooling right awa but for $20 it looked to nice to pass up. Is there anything i'm missing that I would need when all this arrived? Are there anythings I can drop to lower price a little seeing that it would be nice to get it under $700 before rebates. What OS should I go with or can I just stick with my XP home 32bit OEM from an older pc to save cash?

Thank you for your replies in advanced and have a happy holidays ( I know I will )

Edit: I got hit with the /r/n/r thing, I think I fixed it though

good except for the PSU... if you wanna get one on the cheap, that BFG looks k.

if you want to get a higher capacity PSU for an upgrade later on, i recommend this Rosewill: http://www.newegg.com/Product/Prod [...] 6817182067

and if you want to get the cleanest possible power under $100, the PC P&C: http://www.newegg.com/Product/Prod [...] 6817703005

You are all set.