That's pretty much it if you want to be in town. Divetech/Cobalt Coast might be another option if they do daily rates, they're an AI so I don't know. But they're pretty far north in sort of a residential area so you'd want a car to drive back to SMB for any kind of restaurants/nightlife.
No hotels/resorts along Seven Mile Beach have shorediving off their property (that's why it's such a good Beach..) However just about every diveop will pick you up anywhere along there for boat dives.
My Bar at SH is a diver's hangout. Good food also.
There's also the East End, Compass Point, The Reef Resort or Morritt's Grand. But they're a good 30-40 minutes drive back to Georgetown and anything resembling restaurants/shops etc. It's real quiet out there.
If I was doing a short trip to Cayman, I'd stay at Sunset House. It gives you access to town and a few dives in Georgetown for variety - Eden Rock/Devils Grotto and a couple more. If you do have a vehicle, the drive up to Turtle Reef is worth it. Sundivers runs the operation there now.