We've been once and started and ended in St. Lucia. We had 8 days. We spent the first night as a sleep aboard and then the 2nd and last nights by the Pitons. In between we sailed from St. Lucia to the Tobago Cays and back with a stop at the Sunsail base (no longer there now) in St. Vincent, a stop in Canouan, Bequia (2 stops) and the Tobago Cays.

Any of your plans would work. I'd just look at where you want to stop and see what works best. If you'd rather spend more time in any given location then option 2 or 3 would probably be best. If you want to cover as much area as you can, then option 1 would be good.

St. Lucia was pretty easy to get in and out of. Not sure on the others, so I'd look at that. When we went, we could have started in Grenada or St. Lucia and chose St. Lucia due to easier and less expensive air travel.

In looking at boat options you might as well check moorings and sunsail - sunsail does price match too.