Ok, firstly that setup is a bit cheaper because it doesn't include the parts you already have, which include the PSU, normally a pricier item - I trust your PSU is a good model (if not, seriously consider a new one...)
Secondly, it doesn't include Windows... if you have Windows already, and it has only been licenced to one computer, you should be ok to install it on a new computer once, via the phone activation system (Windows is licenced per system, but in reality this means per motherbaord) so bear that in mind
Thirdly, only add in your old hard drive to the new system once Windows is installed and everything is running happily, as this prevents Windows spreading itself onto the old disk, which can then cause problems if that disk fails or you want to remove it for some reason
Finally, that card should play all games well at high settings at that res - for reference have a read through this:
http://www.tomshardware.co.uk/gaming-graphics-card-review,review-32899-4.html
AND an additional thing that I've just realised and I should mention about that spec - that processor is overclockable.... if you wanna overclock you'll need to switch to a pricier motherboard, a Gigabyte Gaming series for example, whereas if you don't you can get the i5 4690 instead of the 4690K, which will save you a few dollars/euros