I own "Handling the Big Jets" as background reading etc as that was the more "professional" of the two.
For interview preparation I just read over my ATPL summary cards.
I also reviewed Jeppesen plates for the "what does this mean?" question.
Have a look at a sig wx chart and know what the symbols mean.
The Cathay interview booklet is probably more useful to be honest.
The interview isn't a deep test of your advanced aerodynamics knowledge.