I'm pretty sure I've seen plenty of spec me for ~£600 threads
oh and as seems to be asked in every thread at the moment, can you 'recycle' any sata hard disk/s from an old pc? would mean you have more money to put elsewhere especially seeing as you want a monitor as well.
the general gaming spec is:
i2500k £180(tho seems to be reduced to £165-£170 every few weeks in this week only deal)
gigabyte z68ap-d3(if you don't need sli/xfire in future)
4gb/8gb pc3-12800 1600mhz what ever is cheapest at the time, need to be weary of fins tho as they interfer with air coolers tho not a problem if going with something like corsair h60 cooler
6870(~£150) or 560ti(~£180) depending on if you are a nvidia or ati/amd fanboy
500-650w psu the lepa w series 550w £47 seems to be suggested for budget builds
case your choice tho antec 100/300, bitfenix merc/outlaw/shiobi get mentioned £40-£50
monitor I have no idea
edit: stulid to the rescue while i was typing