It is a great card for the money, it wont be touched at the minute. It will be happily running games at 1080p and even 1440p for years to come. Game development in the visual department has slowed down dramatically, especially as the latest consoles are weak, meaning that developers have little reason to push there graphics in games.
You could save a bit by going for an earlier version of the CPU, Ivy bridge mabye. You dont actually lose all that much performance as the latest generation Intel chips have gone more towards energy efficiency then raw power. That would save you money on both the CPU and the Motherboard. I have something stupid like 40 Games of various sizes and a third of my 1TB drive left. That would save you a few quid. I would recommend WD over Seagate as well.
You dont need a £18 cooling paste, a £5 one would do the job if you really want to use one.
A 750Watt power supply will be ample. You are right in sticking with corsair, they are a good bet. Just avoid the builders series as it has a mixed reputation though. I have heard good things about the RM series which is what you have picked so far.
Just a personal opinion but that case is boring This guy has style : http://www.scan.co.uk/products/nzxt-h440-matte-black-with-red-trim-mid-tower-case-with-side-window-and-4-quiet-fans-w-o-psu
A budget style option would be the Corsair 230T though .