Re: NOT TECHNICAL. where to buy ???
Weatherguard makes some really good stuff.
Be carefull with lots of weight in a box since it can cause cracking were the bedside and the back peice come together. Chevy makes braces for this or you can make your own. This is supposedly much more prevelent on the newer trucks(although 03's they supposedly used a bit thicker metal)
I would buy a weather guard....al or steel is up to you but I am going to put a steel weather guard box painted gloss black on my black truck and I think it will look tits. It will be sitting atop a headahce rack/brace built by me also painted black with my cool man whirly light on it. I have heard that http://www.transferflow.com
makes some good stuff and it might be an option for you too but a bit more $$$