u can look at this page
http://www.wheretocredit.com/korean-air/j

Alaska does seem to offer the most miles but they have to have an active account every 18 months.
U can buy miles into the program though.
Can take flights on JL/CX using Alaska miles.

KE miles have a 10 year validity so u can hold onto the miles for quite a long while.

The ICN-KIX segment is quite short so even if u lose the miles, it doesnt really hurt a lot, fortunately.