Most of the books you need to study for Cathay interviews, like HTBJ, Ace the Tech..., Capt. X,Y,Z, etc. are almost always available from Aviation World. Stores at Vancouver and Toronto airports.
http://www.aviationworld.net
They do mail orders.
I'm glad I bought the Capt. X,Y,Z book, though I agree it is far from perfect. Lots of out of date fleet and financial numbers. Lots of generic advice applicable to any airline application.
The one thing that drove me nuts was that they write about the importance of proofreading your CV and applications, but their book is riddled with grammatical errors! It looks like they used a PC's spellcheck function, but never used an editor.
Anyway, they have 100 multiple choice tech q's in that book, and while I didn't have any of these exact q's on my tech exam, the material you are forced to study as a result is quite relevant.
BTW, it's the same material for the 1st interview as for the 2nd. I don't know what CPP guys need.