If you eliminate AllWest for the reason stated above, Lodge Kura Hulanda adjacent - they also use Go West - I'm hard-pressed to come up with a viable option. Lions Dive, Breezes and the Hilton all use Ocean Encounters which has a similar solo policy IIRC. There are other dive operators on-site at many of the dive sites - Playa Lagun, Varsenbaai, Tugboat etc. but none have an on-site hotel/resort. Some have rental houses/condos within walking distance nearby but no gear storage at the dive site. And all are not close to much of anything else - i.e. restaurants, shopping etc.
About the only place I can think of is the Marriott Emerald Casino - probably no kitchens either - IDK what Caribbean Sea Sports policies re: solo diving are but IIRC they had on-site gear storage.
The house reef at LKH/All West - Playa Kalki - is better IMO than either Buddy's or the Divi. Didn't the Divi's reef take a lot of damage in a recent hurricane? In general the diving off Curacao is as good as Bonaire. There's dives on Curacao you don't see on Bonaire - Mushroom Forest/Blue Cave is one. But it's a boat dive. At some sites if you were dropped on the reef you'd be hard pressed to tell where you were - same water clarity, same blue fish/other animal life. We seemed to see more big eels there also. One other difference is that the reef generally starts farther off-shore on Curacao - at a lot of west sites you enter off a sandy beach and swim out thru a wide opening in the ironshore cliffs. And Curacao has the dolphin dive.
my .02