Dell xps 720 for my son

I need help. I want to buy a computer for my son that he will be able to play his games on. He just got Oblivion and on his year 2 yr old AMD 3500 Medion with a Nvidia 7600 video card he can't play it very well (with two meg of ram) I am going through chemo right now and he is taking care of me and I want to do something for him. I can't afford to buy one of those extreeme game machines, and I can't and he can't build one on his own. So I am on the Dell web site and this is what I have put together. One thinig that I am questioning is is the ram. Even though it is a better ram and overclocked, it does not give me an option to go to 4 megs of this ram, which I am not sure is necessary or not. I can't find it (that ram) for sale either anywhere on the web to the same specifications to see if I could add more later if nec. Here is what I picked out for him. Please offer me whatever comments you can. The price comes to $2,634 as configured.

PROCESSOR Intel® Core™2 Q6600 Quad-Core (8MB L2 cache,2.4GHz,1066FSB) edit
OPERATING SYSTEM Genuine Windows® XP Media Center 2005 Edition with re-installation CD edit
MEMORY 2GB Corsair Dominator DDR2 SDRAM 800MHz OC'd to 1066MHz-2 DIMMs edit
HARD DRIVE 320GB - Seagate 7200RPM, SATA 3.0Gb/s, 16MB Cache edit
OPTICAL DRIVE Dual Drives: 16x DVD-ROM Drive + 16x DVD+/-RW w/ dbl layer write capable edit
MONITOR 20 inch UltraSharp™ 2007WFP Widescreen Digital Flat Panel edit
VIDEO CARD 768MB Nvidia GeForce 8800 GTX edit
SOUND CARD Sound Blaster® X-Fi™ XtremeMusic (D) Sound Card edit
KEYBOARD Dell USB Enhanced Multimedia Keyboard edit
MOUSE Dell Optical USB Mouse edit
FLOPPY & MEDIA READER No Floppy Drive or Media Reader Included edit
MODEM 56K PCI Data Fax Modem

That system looks pretty good and will handle everything you can throw at it at the moment. Nothing really to add to that.

As for the RAM:
http://www.newegg.com/Product/Prod [...] 6820145168

http://www.newegg.com/Product/Prod [...] 6820145043<------you would need this one.

You might be able to find it cheaper at other stores. Dell overcharges on their XPS system.

If you need any help, I'll be glad to assist you. PM me anytime. I PMed as well.