I, too, like the Ziplocs. To keep them from rolling up, I went to Staples and bought a couple heavy plastic presentation folders, and cut patches to fit in the Ziplocs to keep them stiff. As a bonus, I can cut notches in the ends of the plastic patches and use them as cards to hold thread, fishing line, paracord etc.

I'm trying self-stick business card pouches to stick to the plastic and hold small items like first aid supplies. I'm not convinced that the sticky part will hold up, though.