Hi all,
I apologize if this is the wrong place, or answered somewhere else, please point me in the right direction if so.

I am getting set to go on an expat assignment from the US to China. For 2 years I expect to be flying back an forth between China and the US about 4 times per year (4 round trips). I will be flying with my wife and kids 2 of those times and by myself the other 2. I am most concerned about upgrades to higher classes on my flights. Any advice on how to best do this? Which airlines are good for this?

Also, I remember talking about something called a challenge I believe where you fly certain number of miles in a certain time frame and you could get a higher level in a shorter time. Is there something like that still available?

Thanks,
Mark