Best to go and scout the area as there are so many developments around Bangsaen, old and new. Good luck with your search. I like Bangsaen although at weekends and Thai holidays the beach area gets packed to the brim with locals holidaying and traffic gets pretty bad too!
Does the document to be legalised have to be paper based or can it be done electronically? I know there is an option to choose but I am wondering if schools in Thailand will accept an electronic version?