Definately use a handler. There is no FBO. You will park on a ramp at the west end of the field and without a handler, I'm not sure how you would even get off the field.
It goes without saying, review the star and approaches, and pay perticular attention to the mocas: rocks in the clouds at 10-12000 feet on three sides of the field.
If you stay in San Jose, stay at the Mariott. It is one of my favorite hotels anywhere.I agree with the posts above, drive down to the beach and check it out. Also, drive up to the volcano. You can walk right up to the edge and look into the caldera. It is really cool...