Those are cool.At post #2, I'm going to suggest a different route altogether.
BAK flip design with the BAK box. Full fiber cover with fold up box inside. Holds a lot and doesn't leak. Also makes your whole bed secure and can be folded out of the way. It'll run you over a grand in total though.
2nd the UWS for a nice box for about as low a price as can find on any of the cheaper boxes. Had a low pro alum, it was nice.For just above that price I have and like the UWS brand. I have a low profile black aluminum. http://www.uwsta.com/p/58-single-lid-crossover-low-profile-paddle-lift-lock-blk?pp=12
For the one of toughest and a lot more cash...http://www.weatherguard.com/truck_tool_boxes/view_products.php?subcat_id=9
It is the best in that price range. I work in oilfield sales and drive 50K+ miles per year on the roughest roads. All I had to do was turn two nuts to adjust the lid to a little tighter fit(a little dust was getting in) and, I have been a happy camper.Thanks guys! Some really good information. I'll check it out. I'm not familiar with the UWS brand but it sounds promising.