Well, you're looking for 3 people, and it's holiday season, so that's not promising. You might want to consider United and pay some extra for Economy Plus Access, which is 5 inches more of legroom.

I'd recommend you apply for a credit card to get some more miles, but that won't work if you're in Germany.

I hope you have at least an overnight layover in SFO; that would break up the flight and it's a nice city to visit.