I'd look into Sunsail or the Moorings. I think their prices for 40 ft cats during that timeframe would probably be pretty decent. You'll probably end up in BVIs since that's where most boats are, and its a good family
cruising ground because the hops between islands will be short. With very young kids on board short sails
seem best to me!
will be essential IMO, to have enough room for both captain
and your family
Maybe you could also do a week at the Bitter End Yacht Club in BVIs or some other family oriented full service
resort where you can get childcare and have some couple time? Both you and your wife, and the older kids, would be able to take sailing lessons
appropriate for your level, and they probably offer daycare for the little ones.