Also, the Indonesian Embassy put on a festival last year. They will probably have other events in the future, but I bet someone would be able to give you some leads on local markets with the items you're looking for:
06/23/2013 08:04
Subject: Area Indonesian Restaurants or Markets?
Are there any Indonesian restaurants in the greater DC area? What about markets where I might be able to get real Indonesian coffee, jams, fruits and other goodies?