Yes have been diving there, relly quite enjoyed it too. The snorkelling just off shore is great as well.
The classic dive shop in Barbados is West Side Scuba - http://www.westsidescuba.com/
been around for ever, always good when I have used them (it's been a while)
I have also heard goo things about Barbados Blue - http://www.divebarbadosblue.com/
and Eco Dive Barbados - http://ecodivebarbados.com/
The last two I have never personally used. You will find your choice may be made up for you by where you are staying. But I would highly recommend whomever you dive with you do the Stavronikita at least once.