Well of course if you challenged to AA Platinum you'd make it easily using AA or IB over the water then connecting on any OW carrier in J to IST. That'd be my choice - you'd have Plat status until 2007, then fall to Gold if you didn't requalify (but could probably re-challenge Plat then.) Lots of bonus miles on OW flights if you're Plat.

The TK codeshare (AA flight no.) would get you there too, and nonstop at that.