Although the cities in the South Gulf Coast  region are relatively close together—the distance from Sarasota  in the north to Naples  in the south is just over 100 miles—each of them is a rather discrete experience. When you add in the wildlife and natural expanses of the Everglades , the region’s diversity of offerings becomes all the more apparent.
Exploring the urban beaches and galleries of Naples is a far different affair than digging your toes in the sand for an extended decompression period in Fort Myers  or Sanibel and Captiva . Likewise, Sarasota’s galleries, gardens, and shopping opportunities would require an entirely different itinerary than simply relaxing on nearby Siesta Key  or setting forth in a canoe or kayak into the backwater wilds of the Everglades .
The best plan for seeing the entire area would be to establish an initial base of operations in Naples , and then explore that city’s beaches and sights for a couple of days, as well as planning for a day at the Edison and Ford Winter Estates in Fort Myers ; Naples is also the “gateway city” to the Everglades, and the hotels and dining options there provide a civilized point of departure into the swampy environs of the River of Grass.
From there, you could move north to Sarasota , stopping for half a day briefly to explore Sanibel and Captiva, for the three days needed to fully explore the city and the beach towns that line the coast. A dedicated visit to Fort Myers Beach  or the islands of Sanibel and Captiva  will mostly be spent at the beach, so time spent in those locations should be in direct proportion to the amount of stress you need to relieve.