What PSU to buy?

[Guest]

I have recently bought an upgrade for my PC. the XFX HD 6970. I'm going to replace my HD 5770 reference card with it. The current system is a standard Dell Studio XPS 8100. It has it's original 350 watt Lite-On (not 80+ as far as i know) PSU. I know i will need an upgrade, but i want some room in there so i don't keep my PSU running at 90% or 100% all the time i'm playing games. So i want to know, what wattage should my new PSU be? even better - got any specific recommendations? Limits - i live in the UK, and i have a limit of about £55 ish. Maybe £60.

If you need a comprehensive parts list, here (this will be AFTER the upgrade):
Core i7-860 (No O.C running at original 2.8Ghz)
6Gb 1333Mhz RAM (Unknown make/model)
Dell G3HR7 Motherboard
1Tb WD Blue HDD

If you need any more info, ask below and i'll try to provide it.

 

[WoodenMarker]

A decent 550w would be plenty: http://uk.pcpartpicker.com/part/evga-power-supply-100b10600kr

Moved to Cases and Power Supplies--the Troubleshooting subforum is for.. troubleshooting.

[Guest]

A decent 550w would be plenty: http://uk.pcpartpicker.com/part/evga-power-supply-100b10600kr

Moved to Cases and Power Supplies--the Troubleshooting subforum is for.. troubleshooting.

thank you and sorry - very tired as it is 5:45am and i have insomnia.