Someone just posted this big trip report about beaches around Khanom and Sichon on a travel forum.

In case it is of interest....

http://pleasenotanothertravelblog.wordpress.com/2011/10/06/khanom-beaches-and-sichon-beaches/

cheers nice and handy thinking of going there

Very nice apartments on the beach in Hat Nai Plao

http://www.naiplao.com/

800-1000 baht for an apartment