I don't want to put you off, but I'm not convinced that this is the best time to be buying the 6D, as I think that there's another £100 or so to come off the price in the next month or two. Of course, I could be wrong and you might be willing to pay the extra to have the camera now, but I thought I'd mention it as you seem to be on a tight budget.
Fair comment on future price reductions. I'm more constrained by a wife led budget to be fair ;-)
I'm of the opinion that the 5DII has had its day when compared to the 6D, regardless of the price difference, but I'm not that advanced a photographer to justify the extra cost of the better AF that that the 5DIII brings, nor want to pay the premium difference - although that could change in the shop when I play with both.
Yes, I have considered Digital Rev, I do like the confidence of buying local, just in case something goes wrong - I like the odd risk, but buying grey market isn't for me at this time.