Just go to the manufacturer's websites, they have more than enough basic technical data to help you blag it through the interview. Failing that you can find it in one of the Flight International airliner directories, or if all else fails just google it, like you say spotters talk about that kind of crap for hours. Doesn't do any harm I guess, but I wouldn't spend too much of my interview prep time learning stuff about their aircraft, because you are much more likely to get asked questions about the type you currently fly. ( With a couple of exceptions like Cathay - but there are whole books you can buy about how to pass THAT interview. )