Hello, I had a quick question that I could never get a straight answer for. What is the best type of card stock to use for cards intended for building houses/structures with?

I own several decks of cards but only 2 of them (my Dad's old Bicycle playing cards) seem to be good for building structures with. I've bought various brands of cards like the new Bicycle or themed ones like Firefly but the material they use has a weak, plastic-y feel to them and my structures don't hold up as well anymore. Currently I'm designing a deck of cards as a celebratory thing for my Skyrim mod team (the deck will be in-game) and wanted a deck for myself that I could use to play with but to also build with. I want to replace my Dad's cards as my building cards because they're old and valuable to me, I test my structures with weights and don't want them to bend up bent so I'm looking to build a deck that I can create structures with.

Any help would be much appreciated.