i have just done a NA to TT swap. but i was luckily i already had a manual box in mine. So that helped keep the cost down. I went through Jezz on the club as he comes recommended. If i were you i would ask Jezz for a ball park figure and then work out if it was worth doing. Rember a TT my come down a little in price next year as will your insurance.
I love my new engine and i spent a lot of time getting the car to look how i wanted, as well as realizing it was easier to save up for a swap rather than save the extra for a black manual TT, which is why i did it.