I know of a few places with Durian in Central America.
First of all is Lancetilla Botanical Garden in Tela, Honduras - http://www.telahonduras.com/html/lancetilla.htm
Second is a small farm near Domical, Costa Rica. The source of this seed was a trip made by the farm owner 20 years back to the Honduras botanical gardens. From Dominical, take the taxi up the road to Escaleras 2 miles, the farm is on the left. Or you can buy the durians at the San Isidro farmer's market on Thursday but you must arrive early.
Both have Durians ripening in July/August every year.