Is there any website where i can type in hardware names etc to see how well those things would work with a specific game n such?
http://www.anandtech.com/bench/CPU/2
Like that one?
there is no website like that, and there never will be, costs too much to run
For the most part, the only thing that will have a measurable effect on a game's performance will be the graphics card, for the rest of the build you can just spend a reasonable amount (hint: check pre-built PCs in your price range)
IE if you're spending £220 on a graphics card then spending around half that on a processor will give you reasonable performance
You can go to Cyberpower or ibuy power and build a system with fairly close to the specs you would want and it gives you a general theoretical fps for like 5 or 6 games. How accurate it is might be a little questionable.
CPU:i5 4670k@4.3Ghz GPU:Gigabyte GTX760 WF3 Mobo:Asrock Z87E-ITX RAM:8Gb GSkill Ares@1600MhzCase:Atomic Orange Bit Fenix Prodigy Cooling: Corsair H100i HDD:1Tb WD Cav Black SSD: Samsung 830 128Gb PSU:Seasonic M2II620 KB:Razer Black Widow Mouse:Razer Naga 2014
You could just list your components here and we would do that for you.