Whatever you do, remember that you are hiring someone to look after your interest in this boat. So look for recommendations from independent sources, NOT the seller or broker.
My guess is that there are people in Oriental who know who the most thorough surveyors are, and who to stay away from. If you are financing
the boat, ask them. Ask your insurer. Ask around the local boatyards
Make sure you know what a surveyor is supposed to do, then go through the names recommended, and interview them. The fees
will be pretty much the same (probably up to $15/ft., including a sea trial), and any good surveyor should also be able to check out the engine
If you can find a surveyor who is familiar with the type of boat and engine, all the better.
Get a copy of Don Casey's "Inspecting the Aging Sailboat" and use it to inspect the boat yourself, and then (assuming it passes inspection) use the knowledge from that book to manage your surveyor. Make sure the surveyor checks everything out.