I was going to say - the 2006 turbo is well known to fail in around the 60-80k mile band. Therefore if yours had NOT been done I'd say stay way away. however, as it HAS: Go for it. Go for it
Seriously. Best mod you'll ever do. It totally transforms the car.
Simon from E maps is relatively local to you I guess and is who I'd recommend. If you want to come down our way (West London) then I've another suggestion, PM me if you want the details (I'd not want to offend anyone by posting it here .. )
But again. Do it !!!