There are several forum topics from people that have been there on Divebuddy. Check them out and don’t forget that you can send direct messages to members asking questions also.
Here are just a few shops that I found in St Thomas.
www.blueislanddivers.com
www.aadivers.com
www.cokidive.com
www.stthomasdivingclub.com
and the list goes on..
And tripadvisor has a ton of dive shop reviews.
Have a blast and if you will, write a quick review of where you stayed, who you dove with, etc that may help others in the future.