I have an upcoming SFO-HKG-SIN flight that is currently shown as the new config. I chose my usual 15A so I would still have an excellent seat if it is changed. 15A is a rear facing seat in the new config and to me that is no problem as I experienced real facing intentionally on the UA952 inaugural. Also climbing over the aisle is not a big problem. Choose the left side side you will be moved out of any right side seats on a plane change.

In F I would choose 1A, again as usual.

You also might want to check
Everything You Wanted to Know on Where to Sit on the 747. I think it is is time for a "Everything You Wanted to Know on Where to Sit on the 747 (New International Cabin)" thread. Maybe this should be renamed to that.