If you’re still looking for walking ability to your specific requested amenities, sunsets and a full service resort, Grand Case Beach Club in Grand Case is awesome.
We typically stay at Beachside Villas on Simpson Bay Beach and love it there but it’s a bit of a hike to restaurants. They do have at least one three bedroom unit - maybe more? - and it’s a great place to chill but I wouldn’t walk too far on the beach from there. Karachter and the Boon are walkable but depending on your ages and mobility, they're a hike in my book. You can walk to Maho and Sunset Beach bar but again, they might be a stretch too far.