i'm pretty sure i saw ruffles chips at giant stores (Hyat Plaza) and Megamart (The Centre). Same goes for pudding mix.

rice krispies are practically sold EVERYWHERE. I'm a little surprised you haven't found that. try carrefour if you're out of luck with the other hypermarts.

I'm not sure what western-style chinese food is..but moon palace seems to be popular with just about everyone.