I had the same debate when I wanted to get a winch bumper for my XJ. It came down to either Nates or C4x4. I ended up with C4x4 and really like mine. I decided on them for a couple of reasons. One was cost and the other was because their customer service was awesome.
Nates will nickel and dime you. The initial price doesnt seem to bad of a price, but once you start adding all the "extras" on, it adds up. C4x4 didnt charge me anything extra for grade 8 hardware. Why does Nates? You can get the prerunner bar with C4x4 or you can wait and do it later (your call). My C4x4 mounted flawlessly and I enjoy it, as I said.
Unless you're just set on Nates, I'd consider the C4x4. Give'em a call and talk to them...if nothing else, you can see how their customer service is.