That's gonna be a superb vehicle by the sound of it. I don't have the facilities to do that though. Fortunately our TD5 has been OK so far apart from a throttle problem, which turned out to be due to the supplying dealer tampering with the wastegate as a cheap way to get more power.
Going back to the original post, what kind of discount can you get? I was quoted £450 by our local Superchips. (although our Defender seems quite rapid as it is)