Sorry I can't tell you about what you're looking for other than it's a beautiful location, but I'm planning my own St Thomas wedding and I've found there is a lot of information at bestdestinationwedding.com. Also, there are quite a few wedding consultants on island who I'm sure would be more than happy to help you. Just google St Thomas wedding consultants and lots should pop up.
Good Luck

The Great House can easily accommodate 60 guests. They're known for their ability to handle large (up to 1,000 I think) groups.

The grounds are truly beautiful, and the views are breathtaking. It may be more private than a hotel or beach wedding, depending on their schedule. I've heard that they're pretty good about special requests (for example, some group didn't want water in the fountain, so they drained it for them, and just had the lights, I think.) There's plenty of room for the guests to walk around, but it may not be the best place if guests have mobility problems, because there are lots of stairs. There's also plenty of room for dancing.

They have a gift shop on the property, and you could purchase affordable bridesmaids jewelry (like starfish pendant), or get the crystal toe rings as favors for your female guests or again for your bridesmaids.

I've never heard any complaints about a function there that I remember.

If your group is really going to max out at 60, you should look at http://norbuevents.com/

Just finishing construction and is much more intimate than the Great house.

I did a wedding for my daughter in STT three years ago - will gladly provide you with info; since people seem to come and go in this neck of the woods, things that are great one month can be different the next! You can contact me directly

Mat, Thank you for the information. We're going to STT to take a look early July. Hope it is as great as you say. We also thought it would be more private than a hotel (with people walking by). Since the guest list is growing, it isn't going to be as small as originally wanted.
We had wanted a villa around a pool (sunset) but there would be no room for dancing. St.Peter Greathouse looks like it would be good, just have to take a look and get the details. Thanks again.

I wonder how they got approval for business use in a residential area.

The Greathouse WILL be able to accommodate you! On villas, did you enquire about any of them? Bellagio Estate is large and would work and I believe Blue Serenity will as well! Contact: McLaughlin Anderson Vacation Luxury Villas and they will be of help! It's worth a shot!
Mathayom,
Will have to ck out your sight!

For "inside info" about the Greathouse to be used for a reception, PM me and I'll hook you up with the people that do the catering there...they can fill you in from the inside perspective...