Another novice here. It's great to do your research up front and avoid some mistakes. It's also great to try a few cheap experiments to prove a concept and develop your intuition. By figuring out your mistakes on simple projects, you learn troubleshooting skills that will help you with more complex ones.
A quick search turned up small momentary contact push button switches for $0.15 at quantity 10. You could make cheap prototypes to develop a circuit that works for you. Once you're convinced, then create a prototype with one (expensive) cherry switch. With both experiments under your belt, your full 8x8 array would be the next step, not such a big leap.
Here's an example of someone who created a fully custom keyboard using switches like the ones you mentioned:
http://hackaday.com/2012/02/15/building-a-keyboard-from-scratch/