Four years ago I went to Johannesburg on KLM through AMS, connected from SEA through LAX on the outbound and San Francisco on the return. All on the AS ff program miles. To be honest I do not remember how many miles I used, but there is an add on going through Europe.

KLM only has Business First, but it is done very well. At the time it was fairly easy to find reward seats with a little flexabilty in your schedule.

Just another option. I did CX in first to Hong Kong last February, and it was a truely great experience--so would highly recommend Cathay Pacific as well.