Which SSD is best?

Kingston Savage X 240GB or Samsung 850 evo 250 GB?

I want to know about reliability, performance, lifetime and whatever else there is?

My build for reference:http://www.pcspecialist.co.uk/quotes/intel-haswell-pc/BG9h5SsfXN/

I need a reply quickly as I will most likely be purchasing my build on the weekend. So thanks in advance.

If you are purchasing your build over the weekend the first working day would be Monday. Regarding your query either will be fine, unless you are benchmarking you wouldn't notice the difference in day to day applications.