check this out!www.zenithoceanvoyages.com
We can only accomodate 6 kiters though. If you're interested and you can get another 2 people we could probably hook up with another catamaran, but we'd need advance notice. There are boats that take 8 guests out there, but you'd be pretty crowded, especially for storage, launching off the boat, etc.
In terms of where to go, the wind's good at all of the destinations you mention. January is more reliable. There is a phenomenon known as the Christmas winds in the BVIs however.
We offer a Christmas/New Years trip from St Maarten to the BVIs via Anguilla from December 23 - January 2 and a St Maarten/Anguilla trip from January 8-15.
The Zenith Ocean Voyages crew