Upgrade on an Asus P5B

Hey all, I’m looking to upgrade my somewhat out-dated rig. My current specs are:

Asus P5B
Intel Pentium D 3.2Ghz
1GB Value DDR2 RAM
Nvidia 7900GTX

Keeping my motherboard I think I’m gonna upgrade to this:

OCZ 4GB Kit (2x2GB) 800MHz/PC2-6400
Intel Core 2 Duo E8400 Socket 775 (3.0GHz) 1333FSB 6MB L2
CoolerMaster Hyper TX 2 Processor cooler
Arctic Power 700W PSU

TOTAL - £229

Just a questions:

Whats the best graphic solution, based on the upgrade, for under £100?
Does my board support Core 2 Duo?

Would appreciate the help, thanks.

personally, i’m not happy to recommend a gfx solution cos i’m out of touch with the gfx market

yes, but to make a recommendation i’d prefer to know which P5B you have

Edit: there are 11 P5B’s

I believe it’s the basic model

well DL & install & run PCWizard & it will tell you all you could ever want to know about your system