1.) Resolution is not whether or not it's 'HD', its the amount of pixels on it. say, 1920x1080 is my resolution.
2.) The 2400k is MEANT to overclock, you said 2400k in the comment, but 2400 in your build. Which one?
3.) 400-600 pounds you can get a better Video Card
4.) Do your research! A first build can be intimidating, but as long as you know what your doing, you will be fine.
5.) What game's do you wanna play?
6.) 2500k is a nice investment for sure, It can overclock to ungodly numbers, but the 2400k can OC as well.
I'll try and build you a build later when i get home from work