I have no idea what Municipality Playa Negra belongs to. You can see that on your plot map or study of the public registry. It's where you pay your property taxes.
A good guy to contact for your whole project:
Erik Reinhold
http://www.reinholdcostarica.com/en/I have worked for several years with him on a large project and he knows his way around.
Good luck on your project
Ivo
Godutch Realty