turkey or greece
Goran is quite right, Croatia is famous for its coast mostly from a sailing point of view, I have sailed and kayaked a good portion of croatia´s coast the last years.
There are few beaches and what beaches there are they tend to be more stony than any sand. Just finding a good place to stop is tricky due to sharp rocky steep coastline.
The people are positive and food and wine great and its still worth while but there are better kayak destinations.
But I can recommend either Greece or Turkey. The beaches are great, scenery amazing, food and hospitality excellent.
We paddled Western Crete last year, which is one of my favourite trips, but there are few sea kayak opertaors there, we took our own.
Turkey is very much the same, on both we slept on beaches in little coves etc. Ate in small seaside restaurants who often let us camp next to them.
Try this company in Turkey:
http://www.alternatifoutdoor.com
or this one in Greece:
http://www.seakayakgreece.com/
Good luck.
James