Either of these will do the job:-
My basket at Overclockers UK:
The EVGA Supernova GQ 850w is a FSP built unit with a single 12v rail of 850w. It is semi modular and has a 5 year warranty. Review
here.
The EVGA Supernova G2 850w is built by Superflower and is basically a Superflower Leadex Gold with no tacky led's, a different fan and a longer warranty. It has a single 12v rail of 850w, is fully modular and has a 10 year warranty. Review
here.
The XFX XTR 850w is a Seasonic built unit with a single 12v rail of 840w. It is fully modular and has a 5 year warranty. Review
here.
The Superflower Leadex Gold 850w has a single 12v rail of 850w, is fully modular and has a 5 year warranty. It does have bright white led's where the cables plug in and they cannot be turned off. Review
here.
The Corsair RMx 850w is built by CWT and has a single 12v rail of 850w, is fully modular and has a 10 year warranty. Review
here.
Out of these 850w units I would probably go for either the EVGA G2 850w or the Corsair RMx 850w. Both have a 10 year warranty and both have UK service centres now.
I would say that if you are going to be doing some heavy overclocking then consider a 1000w unit just to be safe. Have a look at these:-
My basket at Overclockers UK:
The XFX XTS 1000w is a platinum rated unit built by Seasonic. It has a single 12v rail of 996w, is fully modular and has a 5 year warranty. Review
here.
The XFX XTR 1050w is another Seasonic built unit. It has a single 12v rail of 1040w, is fully modular and has a 5 year warranty. Review
here.
The Corsair RMx 1000w is a CWT built unit with a single 12v rail of 1000w. It is fully modular and has a 10 year warranty. Review
here.
The EVGA Supernova G2 1000w is a Superflower built unit and is basically a a Superflower Leadex Gold with no tacky led's, a different fan and a longer warranty. It has a single 12v rail of 1000w, is fully modular and has a 10 year warranty. Review
here.
Personally, out of these 1000w units I see little point in choosing anything over the excellent Corsair RMx 1000w. It is a top quality unit and has a 10 year warranty which negates the main reason for buying the EVGA which is not worth the extra money.