New graphics card, is it compatible?

do not buy that card.
it is compatible, but the card is not so sweet.
a 8800GS/9600gso or 512mb 8800gt would be a bit better. if you can afford it, get a ati 4850.
Your motherboard is pretty nice, don't put a junky graphics card in.
good luck!

It's certainly cheap though. 40 pounds for "1 week only offer."

What resolution is your monitor? if you are using an old crt at 1024x768, then yesthat card would be nice. anything above that and the card is almost worthless as it runs out of memory pretty quick.
the 9600 gso is super cheap online, i have seen as low as 40 DOLLARS. thats like 25 pounds i believe. The performance of that would scale much better with higher resolutions.

Compatible, Yes.
Recommended, No.

256Mb of memory is not enough for a GPU now a days.
2nd the above recommendations, 4670, 9600GSO/GT 512, 8800GT/9800GT 512 or the much preferred 4850 512.
Any current GPU will work in your motherboard.

Can anyone recommend me a good one for playing at 1440x900? It cant exceed £50 total :< (im poor atm), anything from this site good? http://www.microdirect.co.uk/productlister.aspx?n=2,12,...

or

http://www.overclockers.co.uk/productlist.php?groupid=7...

From those sites with an approximate £50 cap your choices are pretty limited.
The best I could locate for you would be these 3 cards:

http://www.microdirect.co.uk/(38259)HIS-ATI-HD-4670-512MB-iSilence--DDR3-PCIE-HDCP.aspx
http://www.overclockers.co.uk/showproduct.php?prodid=GX-097-PC&groupid=701&catid=56&subcat=1274&name=PowerColor%20ATI%20Radeon%20HD%204670%20PCS%20512MB%20GDDR3%20TV-Out/Dual%20DVI/HDMI%20(PCI-Express)%20-%20Retail
http://www.overclockers.co.uk/showproduct.php?prodid=GX-075-GW&groupid=701&catid=56&subcat=416&name=Gainward%20ATI%20Radeon%20HD%203850%20Pro%20512MB%20GDDR3%20TV-Out/Dual%20DVI/HDMI%20(PCI-Express)%20-%20Retail

A few extra £ but the best in the range you are looking for.
The only downside is that the 2 newer cards are out of stock so it may take a while to get them.

what about something like: http://www.microdirect.co.uk/(38299)Gigabyte-9500GT-SLI-512MBDDR2-PCIE-DVI-HDTV.aspx

^NOOOOOO!!!

9500GT = 8600GT which in turn = **** <-- wow, the scottish version of feces is cencsored?!?!

get either the 3850, 4670, or 9600GSO
those are really the only cards in that price range worth buying. If you look around these cards go on sale quite often for very cheap as they are the last generation. I would highly recommend you get one of the above even if you have to save for a week or so.
Good luck!

Any more opinions?

OK, thanks, I really havent used ATI before, thats the reason im reluctnt to switch from nvidia

ati is good. just run DRIVERCLEANER before installing the card and drivers and you will be in business.