A new rig that can handle Aion on high settings

Hi! This is my first time posting ont he forums but this site has been very helpful with all my computer related problems. Im planning on building my first computer in a few days. Ive got a pretty good Idea of what I want though. Im upgrading from a HP a6745f with a 8600 GTS GPU since I couldnt afford a 8800 at the time.

APPROXIMATE PURCHASE DATE: 10/8/09 to 10/16/09 The sooner the better!

BUDGET RANGE: $400-$600

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: MMO gaming (specifically Aion on high settings and WoW), music/blu-rays, homework

PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers

PREFERRED WEBSITE(S) FOR PARTS: newegg.com or compusa.com If there are a lot of compusa parts I may just buy them at the store.

PARTS PREFERENCES: I would like to use an AMD CPU, at least a 9800gtx GPU, and dual core+ processor

OVERCLOCKING: No

SLI OR CROSSFIRE: maybe in the future

MONITOR RESOLUTION: no clue. I have a 22" monitor but plan on using a 37" LCD tv if that helps

ADDITIONAL COMMENTS: Would like a stylish ATX case, but the motherboard can be matx or atx im not picky. I also need a OS, Im thinking about going Windows 7 but not sure.

I also did a little research and like these parts

Case: Apevia Blue X-Cruiser Case ATX Mid-Tower Case with Clear Side, Front USB, Audio and Firewire Ports
[url=http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=1446795&CatId=1842][/url]

PSU: Cooler Master eXtreme Power Plus 550-Watt ATX Power Supply (Do i need something stronger??)
[url=http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=4434991&CatId=1079][/url]

Motherboard/CPU: Asus M3A78-EM AMD 780G Socket AM2+ Motherboard & AMD Phenom II X2 550 Black Edition Dual Core Processor w/Fan Bundle
[url=http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=5202486&CatId=2417][/url]

RAM: havent decided...but I want at least 4GB

GPU: Sparkle GeForce 9800 GTX + Video Card - 512MB GDDR3, PCI Express 2.0, Dual Link DVI, HDMI, VGA
[url=http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=4465555&CatId=3670][/url]

HD: Western Digital WD5001AALS Caviar Black Hard Drive - 500GB, 7200 rpm, 32MB, SATA-3G
[url=http://www.compusa.com/applications/SearchTools/item-details.asp?EdpNo=4914330&CatId=2459][/url]

Its strange... I can connect all this stuff fine, but I have no clue what parts I need XD I tried to keep the post neat but I have issues with forums =/ Hope you can help!

how about this gpu? XFX ATI 4780 1G http://www.newegg.com/Product/Prod [...] 6814150436 at 124.99 after mir?

Wow thanks for the fast replies! Do you think the 500watt power supply and the x2 250 are strong enough for heavy MMO gaming? the 4850 is nice.

http://www.newegg.com/Product/Comb [...] mbo.265996
that will save you $35 which will cover the upgrade to a 545 which will handle Aion a bit better
http://www.newegg.com/Product/Prod [...] 6819103694

review for the basiq v2.01, its a redone version so its better than the rest of the basiqs
http://www.hardwaresecrets.com/article/792

oops i meant theAMD Athlon II X2 250^_^''' Also any suggestions on Case fans, Its the cheapest way to add some flash I guess.

thanks for all of your help! I finally picked out all the parts and im just around $630 which should be alright.