Well, that depends, it's mostly a matter of taste. Here's what I like:
For general stamping and coloring with copics, I like Memento inkpads.
For sponging, I like SEI chalk inks and Versa Magic chalk inks.
For distressing/aging, I like Distress inks.
As far as cardstock, I like using Neenah cardstock for stamping images and copic coloring. For colored cardstock, I like Papertrey Ink and Bazill swiss dot.
Stamps are a bit harder, it just depends on your taste, there's so many stamp companies out there. My favorite rubber stamps are Prickley Pear, Whiff of Joy and Stampin Up. My favorite clear stamps are Papertrey Ink, Verve, and My Favorite Things.
Most likely you will find your own favorites through trial and error...
Good luck!!