New Build - Power Supply Choice Advice

[Crowda]

Approximate Purchase Date:
2013/08/24 - Present

Budget Range:
£500 - £650

System Usage from Most to Least Important:
Gaming

Parts Not Required:
All parts have already been purchased

Preferred Website(s) for Parts:
www.amazon.co.uk
www.aria.co.uk

Country:
England

Parts Preferences:
None

Overclocking:
Maybe

SLI or Crossfire:
No

Monitor Resolution:


Additional Comments:
I created a parts list on uk.pcpartpicker.com to give myself an idea of what parts were compatible and how much it would cost me to get myself a new system. This is my first build and I used the wattage estimation on the parts list to select my PSU (Estimated Wattage: 303W).

Since ordering my parts (thinking I had double checked everything enough) I have entered my parts into other wattage checkers and have had wildly different results.

I am pretty certain I have made a huge mistake in my PSU choice. Would I be better off getting a 700W PSU? Or something else?

Part List:
PCPartPicker part list / Price breakdown by merchant / Benchmarks

CPU: AMD A8-6600K 3.9GHz Quad-Core Processor (£88.79 @ Aria PC)
CPU Cooler: Scythe SCKTN-4000 55.5 CFM CPU Cooler (£19.33 @ Amazon UK)
Thermal Compound: StarTech Metal Oxide 15g Thermal Paste (£2.69 @ CCL Computers)
Motherboard: Gigabyte GA-F2A75M-D3H Micro ATX FM2 Motherboard (£60.99 @ Amazon UK)
Memory: Patriot Viper 3 16GB (2 x 8GB) DDR3-1866 Memory (£100.61 @ Amazon UK)
Storage: Seagate Momentus 750GB 2.5" 7200RPM Internal Hard Drive (£38.80 @ Amazon UK)
Video Card: Gigabyte GeForce GT 640 2GB Video Card (£66.99 @ Amazon UK)
Wireless Network Adapter: TP-Link TL-WN751ND 802.11b/g/n PCI Wi-Fi Adapter (£7.79 @ Aria PC)
Case: Inwin MANA136 WHITE ATX Mid Tower Case w/300W Power Supply (£45.58 @ Scan.co.uk)
Case Fan: Antec 75024 79.0 CFM 120mm Fan (£10.00 @ Ebuyer)
Case Fan: Antec 75024 79.0 CFM 120mm Fan (£10.00 @ Ebuyer)
Case Fan: Antec 75024 79.0 CFM 120mm Fan (£10.00 @ Ebuyer)
Case Fan: Antec 75024 79.0 CFM 120mm Fan (£10.00 @ Ebuyer)
Power Supply: Corsair CX 430W 80 PLUS Bronze Certified ATX12V Power Supply (£40.47 @ Amazon UK)
Optical Drive: Samsung SH-224DB/BEBE DVD/CD Writer (£12.86 @ Amazon UK)
Total: £524.90
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-08-27 13:34 BST+0100)

Have I made any other mistakes?

Any advice would be much appreciated.

 

[4745454b]

Nope, more then enough. I'd be surprised to see that rig go over 175W. The GT640 doesn't need a PCIe power plug so it uses less then 75W. I don't mean to be rude, but this isn't a high end rig you have here. The basic Corsair 430W will be fine.

 

[Crowda]

Thanks, when I entered it into another wattage calc I was getting ~700W required.
Guess I must have entered something wrong.
Thanks again.

 

[4745454b]

You could add another GT640 and not hit 350W. Good luck with your build.