I can't see the link. I don't know anything about OCing I thought it damaged the CPU. Any other recommendations?
Try this
http://www.scan.co.uk/todayonly/index.aspx
Do a CTRL-F for Intel Core i5 4670K, S 1150, Haswell, Quad Core, 3.4GHz, 3.8GHz Turbo, 1200MHz GPU, 34x Ratio, 84W, Retail + Gigabyte GA-Z87-HD3, Intel Z87, S 1150, DDR3, SATA III - 6Gb/s, SATA RAID, PCIe 3.0 (x16), D-Sub (VGA) DVI-D HDMI, ATX
You may want to do some reading on overclocking as that is a factor in price on your initial budget. So work out now if you may do it in the future, i fully recommend getting a K chip and z87 board, and in the future putting a decent air cooler or close liquid cooling loop like a H80i to extract the maximum performance.
All overclocking degrades CPUs faster than normal, this may mean a modest overclock reduces the lifespan of a CPU from 15-20years to 10-15years. Its such a long time that its never really been proven, nobody can be bothered as in 6-7 years itll be ancient anyways.
If you dont want to overclock get a H or B series motherboard and a Non K chip.
One more option, ive seen a Gigabyte Z77 mATX on eBay for £86, and a i7 3770 for £176. Although not a K chip, it can be overclocked to the highest Turbo Multiplier, which will get you to 4.2Ghz. I run this overclock on one of my machines. This will get you a 4 core 8 thread CPU over the quad core only chip with haswell. Also it provides a smaller form factor motherboard. Thatll be £260.
I say this because for you its ideal to go mATX, you will probably never SLI/Xfire, and at most youll only want a PCIE Wireless N Card. This will mean a smaller PC chassis is required and no space is wasted. For Haswell an mATX config is £248 using the i5 4670k and a Z87 board.
So tradeoff is older architecture, vs hyper threading in those scenarios.