Costa Rica:
Only 3 airports have Avgas, no FBO's fuel is sold by RECOPE a gov't company.
Quality and service is very good, price around $5/gal.
MRLR-Liberia Guanacaste, long paved rwy, sea level, good weather VOR App; it is located in the NW part of the country next t the Pacific Ocean, near the border with Nicaragua.
MROC-Alajuela(radio call sign EL COCO), this is the main international airport and the only ILS in the country, lots of traffic, which includes light aircraft.
MRPV-Pavas, San Jose, light aircraft airport, visual approach and daylight operation.
Nicaragua: try to stay away; the only acceptable airport in Managua MNMG.
El Salvador: Comalapa International, next to the Pacific Ocean, long rwy and ILS MSLP.
Guatemala: La Aurora, Guatemala City. the main international airport, MGGT.
Panama, David close to the border with CR, MPDA, Panama City MPMG former Albrook Field in the Canal zone, now Marcos Gelabert. Stay away from Tocumen, MPTO: very busy, far from the city and not very general aviation friendly.
PM me for more info.
G