Thank you for the help! The problem is I don't have a credit card and also I'm from Romania, so I was interested if this is something I might possibly find in shops here. I guess that may be something I need to search myself...
Ahhh, K. Then you best bet is to look at the shops and to look for NVidia graphics cards, least hastle that way (avoid the TNT2 and older series, instead you need the GeforceFX5xxx and higher cards). Examples are Geforce FX5500, GeForce FX6600, Geforce FX7900 and so on, these are just examples you can use any cards in any of these series, within each series the second number denotes where it falls in power in that series. For example, FX5200 is lower power than FX5500.
The only other thing you need to remember is you need an AGP card, NOT a PCI express card (also called PCIe).
If you follow the above you will be able to find a card to display your resolution.