Yeah Cavey. I been doing a lot of studying lately, cause I have to build a new system. My build from 5+ years back has finally gotten obsolete and doesn't meet minimum for Black Ops. Newegg has pretty much the best prices around on most stuff. I don't know if that is available to UK shoppers, but I'd be suprised if it isn't.
Here is the system I'm probably going to build, it uses the new 6 core processor and Radeon (as opposed to Nvidia). I already have a bunch of hard drives and a new Win 7 64bit operating system.. so I don't need those.
COOLER MASTER HAF X RC-942-KKN1 Black Steel/ Plastic ATX Full Tower Computer Case $209
AMD Phenom II X6 1090T Black Edition Thuban 3.2GHz 6 x 512KB L2 Cache 6MB L3 Cache Socket AM3 125W Six-Core Desktop Processor HDT90ZFBGRBOX $229
SAPPHIRE 100290SR Radeon HD 5870 (Cypress XT) 2GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Eyefinity 6 Edition Video Card $369 ($303 with discount code 'EMCZZYR24' and mail in rebate) Absolute best price on one of these style cards.
CORSAIR Professional Series AX1200 1200W ATX12V v2.31 / EPS12V v2.92 SLI Certified 80 PLUS GOLD Certified Modular Active PFC Power Supply $300
G.SKILL Ripjaws Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model F3-12800CL9D-8GBRL $154
Grand total of $1374, which comes in right at 1000 euros
Since your budget is twice that, you could push up to 2 or 3 vid card in crossfire and buy some wicked nice hard drives for a raid array. You could also upgrade the memory to DDR3 2000 up to 16gigs and still be under your budget.