You can get an i5 Sandybridge build out of that. You mentioned 19.5inch monitor is fine, i've included a 22inch once (same width as keyboard) and also you didn't need any dvd drives...
MSI ATI Radeon HD 5850 Twin FrozR II 1024MB GDDR5 PCI-Express Graphics Card *** With Assassins Creed II ***
(£124.99) £599.96
Intel Core i5-2300 2.80GHz (Sandybridge) Socket LGA1155 Processor - Retail
(£114.16) £547.96
OcUK Cream 22" Widescreen LCD Monitor - Black
(£83.32) £399.92
Foxconn H67S Intel H67 (Socket 1155) DDR3 Mini ITX Motherboard - (Sandybridge)
(£58.32) £279.92
Coolermaster Elite 430 Windowed Case - Black (with 500w Elite Power PSU)
(£53.61) £257.32
Samsung SpinPoint F3 1TB SATA-II 32MB Cache - OEM (HD103SJ)
(£37.49) £179.96
GeIL 4GB (2x2GB) DDR3 PC3-12800C9 1600MHz VALUE PLUS Dual Channel (GVP34GB1600C9DC)
(£32.49) £155.96
Razer Arctosa Keyboard - Black
(£31.48) £151.12
Creative Fatal1ty HS-800 Gaming Headset (51MZ0310AA001)
(£30.63) £147.04
Logitech C270 HD 720p 3 Megapixel Webcam (960-000582)
(£17.86) £85.72
Blaze M1178 Tomahawk 1600DPI Laser Wireless Gaming Mouse - Black/Red
(£17.01) £81.64
Yate Loon D12SL-12 120mm Fan - Black
(£3.66) £35.12
Sub Total : £2,434.72
Shipping cost assumes delivery to UK Mainland with:
DPD Next Day Parcel
(This can be changed during checkout) Shipping : £32.90
VAT is being charged at 20.00% VAT : £493.52
Total : £2,961.14
Is cheaper than the first build (although decent) and the price there includes 4 times everything, except the fans at the bottom where theres 8, one for the side and bottom of the case (which already includes a fan for the back), was just showing how you could get a Sandybrdige build out of your 3k... good build I think...