I second moondog's recommendation to fly to Shenyang via ICN on Asiana or Korean. If you can't snag a convenient connection, there are plenty of suggestions on how to kill time in ICN or Seoul. Also, I seem to remember a rumor that Biz Class passengers on OZ (I think?) can get a complementary hotel stay if on overnight connection, but you have to ask for it. The pros on the OZ forum under Miles & Points should be able to help you out on this question and tell you whether that's still on offer.
Connection through PEK can be Plan B. The only exception is if you can manage an extra couple of personal days, and want to do an actual stopover rather than a connection--most people generally feel that Beijing has more to offer the visitor than Seoul.
As stated by someone above: avoid Air China on that long haul from JFK.