Another option is to look on Thai Airways JFK-BKK-DPS, taking the new Thai Airways flight from JFK-BKK nonstop and seeing if you can get a layover there, I know they started this superlong flight a couple of months ago

http://www.thaiairways.com.hk/hot/co...t_en.php?id=43

It looks like it's modeled after SQ's EWR-SIN nonstop flights with Royal Silk (C class) Premium Economy, and some regular Economy seating (so not completely like SQ...)

That would save you tons of time, and you'd probably can throw a stopover in BKK along the way with out paying extra money.

Hope that helps!