I'd like to second (or third! ) the comments on Airwaves below. I read the recommendations here and booked Chris and his dad to fit a new aerial ready for freeview. They did a great job, very neat and tidy (even running the aerial cable down the house behind the downspout which hides it now! ) and I'm very pleased.
Good local tradesmen!
Also, they were cheaper than most of the installers my friends have used in their neighbourhoods.