There's no perfect solution
DK,
With screen, every product has its plusses and minusses, many mentioned above. Aluminum screen is by far the most durable, but presents the nail-wear and nail-loss concerns mentioned once the chameleon is larger. With smaller chameleons, it is not a problem. If you use aluminum, you may look to also use a more appropriate climbing grid, possibly a large-whole plastic fence material, as an inner climbing grid. Note that if the holes in any climbing grid are just the right size for the chamleon to get stuck going through, it eventually will , possible with fatal results.
The 1/4" plastic screen, or plastic coated metal, is a good product, but crickets will go through it easily if there is not an outer barrier of finer screen. Fiberglass also allows easy jail-breaks of crickets as mentioned. It is also more prone to heat damage with improperly adjusted lighting.
When you mention rust on your screen, it reminded me of many of the "made in China" screen cages that were available a few years ago, which use an iron-alloy screen that was painted. Very short shelf-life's on them, due to corrosion of the screen. Good luck.