It depends if you want beach or town. There's Prachuap Kiri Khan and the beaches to the north and south. I prefer the Klong Wan area. There's also Tung Walen beach just north of Chumphon, but the town is one of my favorites. Then there's Ranong with hotels both in the centre and outskirts. On the outskirts of Ranong is one of the best boutique hotels in Thailand. Then there are places south of Ranong like Kuraburee and places around Khao Sok on the banks of the river. I could spend several nights in all of these before getting to Khao Lak then pass through and spend one night south of Khao Lak before making the now awful journey to the airport.
Ban Krut south of Prachuap would be my suggestion.
Ban Krut would be ideal
PKK is only an hour plus away from HH. Depends how fast / slow and time you have. Already mentioned, Ban Krut and Thong Wua Laen beaches are definitely winners. Chumphon for town setting, with night markets. Ranong, same but smaller.
Roadside waterfall near Ranong for a pitstop along the way: https://goo.gl/dFkzG9Edited: 10:41 pm, August 15, 2018