I did a bunch of research regarding DIY bedliners. Based on the number of different forums and web sites, there were a lot of bad responses to a host of the more popular named ones. I would guess to say for every good result, there was 5 bad ones.
One that I found that conintually got good results and I don't recall finding any bad ones was U-POL Raptor bedliner. One of the larger suppliers was TCP Global, which happens to be in San Diego. I stopped by and picked up a kit for doing the bed floor of my '68 truck I am building. It is a two part system, which has a hardener you mix in. It comes in a kit with 4 bottles so you only mix up what you need (at least per bottle). It comes with a sprayer or you can roll it on.
I have done the steel floor (I am replacing the stock wood one with the optional steel one) and the results were great! From what I can tell, it should hold up great but I actually haven't got it in the truck yet, so I won't say how the long term is. They offer it two ways, black or tintable, so you can somewhat color match.
Here is the page and it's about mid way down,
http://www.tcpglobal.com/detailsupplydepot/dsd18.aspx
Here's a picture of the floor,