You should contact Andrew Sheldon of Tornado. He is in the UK and handling all of the business directly as far as I know. Nice fellow it seems and can supply turnkeys.
In fact, I know that you're researching GT40s and looking at a number of companies. All of them, to my knowledge, will supply turnkeys and turnkey minuses - even if they do not directly advertise it. Therefore, you'll have to call around a lot to get the complete picture. Take care,
Ron