There are three charter companies on St Thomas.
1) Island Yachts in Redhook which charters only Island Packets
2) VIP a little further west. No idea what is in their inventory at this time
3) CYOA much closer to the airport. They have a mix of monohulls and cats
In a PM I would be glad to answer any questions and provide my opinions on each of the operations I have listed above. I would be glad to give you some itinerary suggestions for St Thomas, St John and the surrounding smaller islands.
You might also consider going to Traveltalkonline dot com in the forum section and do a search with the name of each of the companies listed above to read comments that are posted as well.