I have used Access Fares (
www.accessfares.com) and liked their service. They worked with me back and forth for some time trying to find something that worked for me. Most of their choices to SE Asia from Washington seemed to be on UA and KE. Ultimately I had them book my on QR out of JFK with a short connecting flight from IAD. The fare was widely available and not a consolidator fare, but they are basically a travel agent so they can book any flight. There was no fee or anything.
I would use them again if I didn't have enough miles for an award.