Originally Posted by Globaliser

Much of this is personal preference and how much you'd all want to fly together in the same cabin on the outbound flight.

Personally, I would take the option with two seats in F. Nice though Club would be for people who've never flown it, this is a special treat for your parents and you might as well push the boat out. As you'll no doubt have to explain the seat swap to the cabin crew, there's a decent chance that they will then try to make the flight extra special for your parents.

Of course, one bonus is that you can all use the CCR before the LHR-EWR flight.