You could do better for you budget. Do you want a laptop or a desktop? I was just checking a couple custom build sites, and I could configure you a gaming desktop for just under £700, including VAT. I hadn't really looked at laptops yet, but as an example, these both have a significantly faster graphics card than the one you found:
https://www.box.co.uk/NH.Q87EK.002-Acer-Aspire-7-Gaming-A715-75G_2934480.html
https://www.box.co.uk/1L6F6EAABU-HP-Pavilion-Gaming-15-ec17007na_2958258.html
If you'd like a laptop, I'll do a more thorough search; if you'd like a desktop, I can send you an example of a custom build, or we can talk about what hardware you might want in it. Please also let me know whether you'd rather get a good system for less money, or the best one £800 can buy.
