Hi,
There are too many
charter firms to give a specific recommnedation - just find one where the boats are less than a few years old and you should be OK.
Where to sail there? Anywhere! There are 1,700 islands to choose from.
High spots for us this past summer were Dubrovnic, Mklet, and also the Kvar National Park - go look at our blog and you'll see some shots etc.
Good luck
JOHN