Recommend a garage for L322 gearbox TC issues in essex

Hi, I believe I have a problem with Torque Convertor as the car is juddering with a light load between 1000 - 2000 rpm. have viewed many threads. I hope I have caught the problem before it affect's the transmission unit again.
I live in the Wickford - Billericay area and wondered if anyone has any good experience of a garage that would know what they are doing and would only repair or replace what is needed.
Thanks
Nick

Mat be a bit late but there is an automatic gearbox specialist in Hornchurch
Rebuilt my old TD5 gearbox for very reasonable cost

there is one on Canvey i think its called thames transmissions at Charfleets industrial estate