@yasserBasha I never said tier 3 was bad. Tier 3 is fine, as it says on the list. I have no qualms on recommending anything Tier 3 and above.
However the OP mentioned that he wanted a
quality power supply and
quality was more important than wattage. He even says he wants a Tier 2 or above power supply... To say that the CX series (Corsair's absolute lowest grade power supplies) are of the same quality as Seasonic's mid range offerings is silly. They are great power supplies, but that's only for their price, which is a little lower than the kind of money you have to pay for a very high quality PSU. Again I never said or even implied that tier 3 was "bad" or dangerous, just when the OP put so much emphasis on a "high quality power supply", that's what should be recommended.
I also don't see how £74 is outside of his £70-£85 budget...
This one is fulfilled by Amazon, and works with your new budget:
http://www.amazon.co.uk/Seasonic-M12II-620-Semi-Module-620W-ATX12V-Supply/dp/B003BIEOBY/ref=sr_1_2?s=computers&ie=UTF8&qid=1367360259&sr=1-2&keywords=m12ii+620+bronze The High Current Gamer is also a very good supply though.
EDIT: Just found out, the Antec is basically an M12ii interally, just re-branded, so go for the Antec one if it's cheaper.
M