I searched around a bit more, ended up calling
http://www.demon-tweeks.co.uk to find out if they stocked the stuff I wanted. I have no idea what made me decide to call, I never do, if it's not on the website I normally CBA to buy from someone. Turns out they have the stuff I want and the prices were great with a free rear brake line and free postage thrown in. I couldn't miss a deal like that and after checking that I can't get it cheaper somewhere else easily I stuck it on my credit card.
Here's a list of what I got and what it cost (prices are including VAT):
EBC X-Series brake disks part #: MD3088X (x2) @ £244.70
Goodridge Front* Brake Lines (stainless steel ends, black sleeved) @ £73.24
Goodridge Rear Brake Line (stainless steel ends, black sleeved) @ £0.00!
EBC Rear steel brake disk part #: MD6232D @ £43.32
EBC rear brake pad part #: FA174** @ £13.89
Delivery @ £0.01!
So the total comes to: £375.16
The disks will last me longer than I'll have the bike for and the Goodridge brake lines have a lifetime warranty so I think it is money well spent.
* The front brake lines are in the same configuration as the OEM ones, meaning that they have the T-split connector on the mudguard, I specifically wanted this. I know they are a tad pricey, but I got them because I mentioned that they are overpriced and the bloke responded by throwing in a free rear line which then works out cheaper than buying both elsewhere.
** I accidentally bought some normal kevlar front brake pads a while ago, they are lying around in the garage. I bought a normal rear instead of an HH pad so that I can have the same pads all round when I put the disks on. When these are worn out I'll put HH pads on all round again.
The only things I still need is seals sets for the master cylinders and the front calipers.