Going during the week increases your options (provided that you avoid the week of the 4th), including Park Place Boat Club (Ladd's / PIB Marina). If you enjoyed Ladd's, you'll be impressed with PPBC. We're hoping that they'll move ahead with their plans to expand and renovate the marina basin, but the renovations of the restaurants and facilities make it worthwhile nevertheless.
The Crew's Nest has a lot of docks, and they offer very diverse environments. "A" Docks are immediately behind The Boardwalk. They offer great protection from wind, wake and waves, and are the closest to town, but the view is compromised by the Boardwalk, it's far from TCN facilities and golf cart parking can be scarce. My favorite area is C Dock, unless the forecast holds any northern winds. D is where the dock shop / office is, which can also block your view, but it's convenient. After E Dock is PIB Yacht Club, then Millers, and way in the corner are Crew's Nest Docks F & G. I doubt they would put a boat your size on the small floating pier G. Like A Dock, F is a great place to seek shelter from northerlies, but it's far from everything.
TCN amenities have no equal, not just on the island, but just about anywhere: A large pool with snack bar and bar, a kiddie pool, tennis courts, basketball court, an indoor hot-tub, sauna, raquetball court, sidewalk cafe, formal dining, patio bar, and important note: the new fleet of carts are among the fastest on the island.
If you decide to stay at Millers or Park Place, you can buy a daily membership to use TCN amenities. One of the few things TCN lacks is a pavilion near the docks. If you enjoy grilling out, Miller's pavilion is great, and PPBC has good options too. TCN's E, F & G Docks don't have very comfortable places to grill.