Hi everyone, first post. 
Building my first custom PC but having problems deciding on a PSU rating. My components are about to be ordered in the next few weeks from Scan.co.uk. Any help would be appreciated!
My specifications are:-
Motherboard - Asus P6T SE, Intel X58, Sok 1366, PCI-E 2.0 (x16), DDR3 2000/1866/1800, SATA 3Gb/s, SATA RAID, ATX
CPU - Intel Core i7 920, D0 (SLBEJ), S1366 (B), Nehalem, 2.66GHz, 8MB Cache, 20x Multiplier, 130W, Retail
Memory - 4GB (2x2GB) Corsair TwinX XMS3, DDR3 PC3-12800 (1600),240 Pin, Non-ECC Unbuffered, CAS 9-9-9-24,DHX
CPU cooler - Zalman CNPS9900-LED PWM Tunnel Flower Cooler 1366/775/AM2+/AM2
GPU - 512MB XFX GTS 250 Core Edition, 2200MHz GDDR3, GPU 738 MHz, Shader 1836 MHz, 128 Cores
Primary HD - 150 GB Western Digital WD1500HLFS VelociRaptor, SATA 3Gb/s, 10,000rpm, 16MB Cache, 4.2 ms
Case - Coolermaster HAF932 Black, High Air Flow Tower Case w/o PSU
Other items include - DVDRW Drive, DVD Rom Drive, TV card, USB Printer, USB HD, 2 x 250GB internal HD. The case has four 120mm fans as well.
I was looking at a 520w Corsair PSU. What do you think. Any thoughts on my specs as well. It will be mostly used for video editing, media centre and everything else I throw at it. I don't use it for games though I have my 360 for that!

Building my first custom PC but having problems deciding on a PSU rating. My components are about to be ordered in the next few weeks from Scan.co.uk. Any help would be appreciated!
My specifications are:-
Motherboard - Asus P6T SE, Intel X58, Sok 1366, PCI-E 2.0 (x16), DDR3 2000/1866/1800, SATA 3Gb/s, SATA RAID, ATX
CPU - Intel Core i7 920, D0 (SLBEJ), S1366 (B), Nehalem, 2.66GHz, 8MB Cache, 20x Multiplier, 130W, Retail
Memory - 4GB (2x2GB) Corsair TwinX XMS3, DDR3 PC3-12800 (1600),240 Pin, Non-ECC Unbuffered, CAS 9-9-9-24,DHX
CPU cooler - Zalman CNPS9900-LED PWM Tunnel Flower Cooler 1366/775/AM2+/AM2
GPU - 512MB XFX GTS 250 Core Edition, 2200MHz GDDR3, GPU 738 MHz, Shader 1836 MHz, 128 Cores
Primary HD - 150 GB Western Digital WD1500HLFS VelociRaptor, SATA 3Gb/s, 10,000rpm, 16MB Cache, 4.2 ms
Case - Coolermaster HAF932 Black, High Air Flow Tower Case w/o PSU
Other items include - DVDRW Drive, DVD Rom Drive, TV card, USB Printer, USB HD, 2 x 250GB internal HD. The case has four 120mm fans as well.
I was looking at a 520w Corsair PSU. What do you think. Any thoughts on my specs as well. It will be mostly used for video editing, media centre and everything else I throw at it. I don't use it for games though I have my 360 for that!