Help building new gaming machine

[Vitter]

Hey guys. I'm working on building a new gaming PC and handing over my other system to the girlfriend. I'm having problems selecting a video card and i'd like some info on DDR memory.

Here's what I got so far (each contains link to newegg w specs). I'd appreciate comments on any of these, especially if you have some advanced knowledge about a particular subject (like processors or video cards):

ASUS 875P Chipset Motherboard for Intel Socket 478 CPU - This motherboard supports hyper threading and has an 800mhz FSB. The other version i'm looking at supports ICH5R chipset instead of ICH5, but does NOT support hyperthreading. I'm not too sure what ICH5R is, so i'm thinking of sticking with this one for the HT technology.

Intel Pentium 4/ 3.0C GHz 800MHz FSB, 512KB Cache, Hyper Threading Technology - It's either this or the 2.8 GHZ. Again, it has 800mhz FSB and supports hyperthreading.

Corsair XMS Extreme Memory Speed Series 184 Pin 512MB DDR PC-3200 - Getting 2 of these for a total of 1gm memory. Any comment? I don't know much about memory.

Seagate 120GB 7200RPM IDE Hard Drive - 7200 RPM and an 8mb cache. If anyone believes that this model would be a better pick (it's only a few bucks more), please tell me why.

Lite-On Beige 52X32X52 CD-RW Drive - Lite-On, 2mb Buffer, 52x, etc. Standard stuff.

Creative Labs Sound Blaster Audigy2 ZS PCI Sound Card - Decent sound card, from what i've seen. Comments appreciated.

Now we get to the area i'm having a problem with. A VIDEO CARD. I haven't kept up to date on all the latest news, but i DO know this. I want either a 9800 Pro or one of the new GeForces. I want 256mb.

My main question is, what is DDR2? Is it something big? Or should I just go for something that's standard DDR and I know is reliable.

I'm thinking of getting this Saphire Radeon 9800 Pro. Only thing is, the other one has DDR2, it can be viewed here .

They both cost about the same. Does anyone have any tips? Should I even go with this manufacturer?