New Intel/PCI express computer

Hey, I am trying to build a new computer for my roomate and was wondering if Dual core/PCI Express would be the best choices for an Intel build? Here is what we have selected so far

Monitor: Samsung 19" LCD
http://www.newegg.com/Product/Product.asp?item=N82E16824001185

Case:Thermaltake soprano
http://www.newegg.com/Product/Product.asp?item=N82E16811133157

Graphics Card: ATI x850xt PE PCI E
http://www.newegg.com/Product/Product.asp?item=N82E16814102554

Mem: OCZ EL platinum Rev. 2 DDR 3200
http://www.newegg.com/Product/Product.asp?item=N82E16820146890

Mobo: ASUS P5WD2 Premium Socket T (LGA 775) Intel 955X ATX
http://www.newegg.com/Product/Product.asp?item=N82E16813131534

CPU: Intel Pentium D 820 Smithfield 800MHz FSB 2 x 1MB L2 Cache LGA 775 Dual Core, EM64T Processor
http://www.newegg.com/Product/Product.asp?item=N82E16819116213

DVD drive: NEC dvd burner
http://www.newegg.com/product/Product.asp?item=N82E16827152053

Concerns: I'm new to PCI Express, is this really worth the extra money over the X850xt AGP card that is 100 dollars less on newegg? What would be a good motherboard for an AGP Card (for the same CPU)?

Also Will the 430 watt power supply be enough to handle this setup?

The system will be used for mainly light gaming, and multitasking and video editing.
Any feedback and suggestions is much appreciated.

Thanks

-opio

First of, you are getting DDR, not compatible with that board. Its DDR2 you should be looking at.
On the PSU problematic, many ppl suggest OCZ520 (guess they will be here soon enough), i want to point out FSP550 and Seasonic s-12 600w (seasonic for quietness).
And yes, its worth it going to Pci-e, as you say you are going for light gaming i would suggest X800XL instead of a X850XT PE, if you don't bench much that is, and want high scores.

//My cents of ramblings
//Christian

I think the dual cores need the 955 chipset, so PCI-E is a must. Also I would recommend the Seasonic 600W.

Alright, thanks for the replies- I ended up getting OCZ 5300 DDR2 gold, one stick of 1gig memory, and the seasonic 600 watt PSU. I have it all set up, but I can't get windows to install now, it posts and recognizes everything properly, but when I install windows it goes through the initial setup process, loading files etc. and then goes to the blue crash screen saying 'you need to format your hardrive, run a /checkdisk on the next startup.' I don't know how do run a checkdisk with nothing installed though. The hardrive I have is a Maxtor 200GB L01P200 Ultra Series 8MB Buffer UATA133 - Retail Hard Drive Kit. I'm not sure if its incompatible with this motherboard or what, but I can't seem to get any further than the post/BIOS screen with this computer.

Is it possible to run a checkdisk through DOS? boot to dos then run a /chkdisk?

thanks

-Opio

I would suggest the Tsunami over the Soprano. The soprano has a cheap look and feel to the front.

EDIT: http://www.newegg.com/Product/Product.asp?Item=N82E16811133133