Gulfdiver,
We just returned from two weeks on St. Thomas and can tell you about three operations there. First and foremost, do not go with Underwater Safaris! That is unless you want to dive with 39 other people on one boat! They actually have three boats that carry 40 souls each and they have been known to send all three to the same dive site at the same time!
Chris Sawyer dives on the east side of the island and the dive sites there are pretty tame. But he does a nice job--it just seemed to us that it was mainly directed at novice divers. However, if you want to do your PADI classes in the USVI or do your OW Cert dives, he is first rate in that category! Frank Vince is one of his teachers and we think there are none better (He was ours.)!
On the west side of the island we can recommend Blue Island Divers. They have a boat that takes 8 divers max and they do a first rate job. Jim and H (short for Harrison) are fine dive masters and make your dives very pleasant. We think the west side diving is better than the east, but that is opinion.
One thing that may be controversial is the Rhone--we do not think it is worth the trip...but we have dived Truk and that makes most other wreck dives pretty tame.
Both Chris Sawyer and Blue Island have web sites.
I predict you will like St. Thomas--we do.
Joewr