The graphics card is relatively unimportant for a graphics PC as I understand it, you just need to make sure it has a fair bit of Ram (~512mb would do). If you've got a specification in mind already you could post it up to see what people think because you don't really need to spend £1500 to get a decent system.
Something like this would probably do for the uses.
Sapphire ATI Radeon HD 3650 512MB GDDR3 TV-Out/DVI/HDMI (PCI-Express) - Retail £59.99
(£70.49) £59.99
(£70.49)
Corsair HX 620W ATX2.2 Modular SLI Compliant PSU (CMPSU-620HXUK) £74.99
(£88.11) £74.99
(£88.11)
Antec P182 Super Midi Tower Case - No PSU (Gun Metal Black) £78.99
(£92.81) £78.99
(£92.81)
Corsair 4GB DDR2 XMS2 PC2-6400C5 TwinX (2x2GB) £59.99
(£70.49) £119.98
(£140.98)
Microsoft Windows Vista Home Premium SP1 64-Bit - OEM (66I-01939) £59.99
(£70.49) £59.99
(£70.49)
Samsung SH-S203DBEBN 20x DVD±RW SATA Dual Layer ReWriter (Black) - OEM £14.99
(£17.61) £14.99
(£17.61)
Gigabyte GA-P35-DS3R (Socket 775) PCI-Express DDR2 Motherboard £64.99
(£76.36) £64.99
(£76.36)
Intel Core 2 Quad Pro Q6600 2.40GHz Guaranteed to run at 3.00GHZ (1333FSB) - Retail £115.99
(£136.29) £115.99
(£136.29)
Samsung SpinPoint F1 1TB SATA-II 32MB Cache - OEM (HD103UJ) £82.99
(£97.51) £331.96
(£390.04)
Sub Total : £921.87
Shipping cost assumes delivery to UK Mainland with:
City Link Parcel Next Day (Delivered Mon-Fri)
(This can be changed during checkout) Shipping : £20.95
VAT is being charged at 17.5% VAT : £164.99
Total : £1,107.81