First time building PC, need PSU help

InfinityPixel

Honorable
May 13, 2013
3
0
10,510
This will be the first time that I will be building a PC, and I've designed a build:

CPU - i5 3570k
Motherboard - Gigabyte GA-Z77-D3H
GPU - Gigabyte Geforce GTX 650 Ti 2GB
Corsair Vengeance 8GB (2x4GB) LP
TP-Link TL-WN781ND 150Mbps Wireless PCI Express Card
Zalam Z11 Mid Tower Case(it has 5 fans included)
1TB 7200rpm Hard Drive
Enermax ETS-T40-TB Silence CPU Cooler
I'm not planning in the future on a multi-gpu set up (motherboard does not support SLI anyway)

I tried using online PSU wattage calculators, but read on many forums that they are mostly inaccurate. One told me my build was 650W and another told me 530W. I was planning to get the Fractal Design Integra R2 650W, after reading good reviews, and seeing the low price tag. I would like a power supply with some headroom, so I can upgrade the GPU when I need to, and I plan on overclocking the i5 to 4-4.5GHz, but could you give me a better estimate of the wattage of this build, and recommend a better PSU? The maximum I would be willing to spend on a PSU would be around £70/$110. (also I did not just immediately search on amazon, I searched around, but found that including post and packaging, it was best for price). Comments also regarding the rest of the build would help, but are not necessary.
 

InfinityPixel

Honorable
May 13, 2013
3
0
10,510


I've checked the XFXs, but they are a bit expensive for my budget (though they seem to be excellent quality), and I won't be going for SLI. I'm probably going to buy online, having seen the higher prices in some shops.