Motherboard
New motherboards cost like 35 pounds, so repair is out of the question, when replacement will give you up to date technology, and much more features.
I can see your motherboard supports only 'AGP' video cards, which are both older, of lower performance, and quite often more expensive. If you choose to upgrade your motherboard, choose one with 'PCI-Express' video card capability.
In addittion, your board supports only Intel Socket 478 CPU's, these are beginning to show their age in performance terms now, so I'd suggest you consider a CPU & Motherboard bundle, which saves you money, and you can even get one that can use your old DDR memory from the other motherboard.
As a video card choice, there is only ATI, and Nvidia chips out there, so if ATI, you need at least an X1900 series or better, if Nvidia, you need at least an 8700 GT series or better.
Good luck.