We stayed All-inclusive at the Marina Palace Resort. It was lovely and the staff were superb. Thomas Cook did everything (despite their recent problems I still feel safe booking with them)
Sunny Beach, to me, is like a run-down Blackpool. Do yourself a favour and go to the much nicer Duni. ( Note: you won't get from Sunny Beach to Duni as the latter doesn't allow daytrippers) Duni is far, far superior.