I looked into DYC on SXM briefly. I understand they are well established in Europe and seem to be reputable. I have not done business with them so I can't comment on that. My reason(s) for not going with them was that your first night was at the dock. This isn't an "evening start" at a reduced rate, this counts as one of your regular nights. The reason is,
1) They are inside the lagoon
2) They don't do the boat briefing until later in the afternoon,
3) The bridges only open at certain times and you can't get done with your briefing and still get through the bridge that day.
Coming back, you are also restricted by the opening times of the bridges and the need to find a marina for refueling. If your flight is early, you might have to come back the previous day. All that seemed to restrictive to me so I went with The Moorings (I know they don't have the boat you want).
As a side note, we saw a DYC boat at one of the anchorages and it was emblazoned with
www.DREAMYACHTCHARTERS.COM on the boom and maybe somewhere else. I thought it looked tacky.
Not trying to dissuade you from DYC, just letting you know some things to ask about and plan accordingly.
