I'd rethink Curacao although I agree Bonaire is too dive intensive.
Sunscape is the AI in town. Several SB Surges have gone there - it's an ex-Beaches but not as big as the one on Provo. It's a decent resort for the price.
Out on the West End Lofge Kura Hulanda is almost AI due to distance from anything - it's 45mins drive back to town. They are on one of the best shore dives and their boats (GoWest Diving) dive Watamula farther west - arguably one of the better boat dives. Some of their larger accommodations would suit 6, have nice kitchens and maid service.
At times during the year it's remarkably affordable for being one of the Leading Small Hotels of the World.
Lions Dive in town is positioned well also. A little south of town and they have a shuttle. The north side of the harbor has the expanded Megaport so can be congested. You won't even notice them at Lion's Dive. The resort is adjacent to the Sea Aquarium and there's shops/dining at Mambo Beach Blvd, within walking distance. I believe they offer meal plans also.
Rent a car both for easy entry shore dives all along the west side - off beaches - and to do other things. There's shopping downtown, good restaurants, casinos for the adults, the Ostrich farm, the Sea Aquarium some forts,some historical sites, shuttle tours downtown and lots of nice beaches. Christoffel Park has hikes of various difficulties.
You can do a week there for probably 1/2 of what Cayman costs - is that a factor with 5 adults?
Or if only some want to dive, besides the boat dive operation at Sunscape (Ocean Encounters satellite shop) there's also Bas Harts diving or the Dive Bus for escorted shore dives. At a couple we saw a boat on the ball at a site we were shore diving so don't book any of those dives.
With 5 divers, you may want to do more shore dives as boat dives seemed to be around 2/$100. We did 20+ dives but only two off a boat. The Tugboat is a signature site east of town, the boat is 17' deep, the pier nearby around 40' and go around the point to the east and it drops fairly quickly to a field of white eels.
Superior Producer is the other signature wreck but usually only dove at night since it's in the cruise port area. Also pretty deep.
Most beaches have facilities including a dive op, some food option and lockers/showers/bathroom.
www.curacao.com lists most things.