There's a big thread in this section somewhere dedicated to this topic, detailing the recommended and those to avoid.
Speaking of ones to avoid, after using colourtech myself, I try and take every opportunity to warn people who value their bikes to steer well clear of them. They screwed up a job I had them do for me, and they could not care less that they had. I had to pay someone else to right their wrongs as a result. Absolutely awful company, poor quality and unbelievably rude to boot.
I'll see if I can find the thread with the recommendations.