Hi, I'm based in Christchurch and I know these 2 places are sh*t hot are their body work. I nearly wrote off the rear of this car and I paid for Grange Road Bodyworks to sort it and you wouldn't even noticed that it had been hit.
1. Grange Road Bodyworks - 01425 280680 (best time to call the guys is in the morning)
2. Kustom Kolors http://www.kustomkolors.co.uk/
Come to think of it there is another place I can think of: (http://www.fwjesty.co.uk/index.php). The guy who does their spraying is in a class of his own.
Although i've seen plenty of examples of each of the recommended places let us know and post some photos of how you get on.