If you're set on intel you should look into the I5-3570k -- lots of people overclocking to 4.4ghz with that monster. It's famous! Check threads on this site for overclocking reviews.
Like the poster above you should read up on AMD. Intel prices are premium. You can get an 8 core AMD processor and overclock to 4.5ghz easily enough for around £120
You dont have an SSD - these are pretty much crucial in this day and age. If you really dont have the budget. Buy a 64GB SSD just for the operating system and store all your media on the 1TB!
remember to buy an aftermarket cooler for overclocking
remember to buy a Case - unless you have a few cardboard boxes lying around the house
best of luck