Could try this one here for around £900 click here= for details
I got my new rig from Overclokcers, rather than elect a pc form shops such as cyberpowr/pcworld/Mesh etc. They Build them well, and overclock them for you too (3.20GHz @ 4.00GHz)
I have the high-end 980X i7 core, with GTX480 sli, and are very quite in "idle" mode. I would asuume the above pc i lunked - with a 4850 will be very quite. You can customise too.