Thanks all, I did work out in the meantime that some cables came with it but I ordered some pretty blue ones anyway as they are fairly cheap :) I also stumbled onto the fact that the SSD drive I bought needed a wee cage thing so it fits in the tray :)
He doesn't have a little toolkit but I did get him a wrist thingy
He has 8gb of RAM and this graphics card:
http://www.scan.co.uk/products/4gb-msi-amd-radeon-r9-290-twin-frozr-iv-28nm-5000mhz-gddr5-gpu-1007mhz-2560-streams-dport-dvi-hdmi
A case, a 650w PSU, an i5 processor and windows 8.1. Im hoping that is everything!
As for doing it on Christmas day, I'm not sure if I will be able to stop him! He's been looking forward to this for a long time and he has virtually nothing else exciting in his christmas pile :) The house will be pretty quiet though - it's just the 4 of us and younger brother is getting an xbox one and a pile of games so we wont see him for a while. I cook most of Christmas dinner on christmas eve so we basically have a quiet day.
Thanks once again for all your help it is really appreciated.