Bed rail max weight?

Hey guys, maybe I'm phrasing this wrong but I can't seem to find a solid answer one way or another. I'm not interested in the bed utility rail system as the capacities of that seem to be well documented. I'm hoping to make a bed rail system for modular mounting (anything from a ladder rack to a cargo basket) and originally was planning on putting the weight onto the top of the bed rails. Well in my research I've failed to find anything stating what the bedsides are rated for but I've found a couple nightmare threads of bent and cracked bed rails/caps. Does anyone have info on this? I'd prefer to leave the bed rail caps alone to keep the look as stock as possible but if they need modifications then that's the price to pay.

 

Thanks for the suggestion! I've been eyeing those since before I considered a bedrail system. My main concern with that method is that many of the damages I've seen from carrying weight on the bed rails weren't limited to the plastic caps and often cracked and/or bent the bedsides. Would you feel confident supporting the weight of a standard ladder rack (usually rated about 500# from what I've seen) on the bedsides using the voodoo kit? At this point I'm also considering bracing it to the 1" lip that runs along the interior of the bed like so:

 

When I use it it'll be usually used for carrying a cargo basket or roof top tent with a combined weight of (estimating) about 250-300# on the high end. Alternatively it'll get occasional use hauling lumber/metal for projects and potentially kayaks on the weekend (SO's father has a couple larger sea kayaks he's offered to let us use in the past). I'm hoping to modify a pre-existing modular system like the Access Adarac or similar so that I have mounting points for various hardware. The issue is that when it is most loaded down will also probably have Offroad conditions. Different guys on overlanding/offroad forums have reported their bedsides pushing outward from the weight of things like toppers that have been loaded down so I'm trying to come up with the best option. Voodoo bars are starting to sound like a good choice though.