Quoted:
I have used the command arms handguard and really like it. I don't like the top rail they sell and always replace it with a plain black one. It gives you rails without looking like a railed handguard and you don't need covers for the rails. They fit well and as far as melting them goes, I usually try and take aimed shots and not just blow ammo for nothing, so I can't comment on that. If that was a problem you could add a heat shield, but I doubt that is a real big problem for most people.
I used the CA arms /LHV lower for a long time as well. It's a good HG and holds up well to abuse, but I also have never burned off hundreds of rounds to test how well it holds up to heat. Can't comment on adding a heat shield because I've never tried that either.
Like ACR I ditched the (IMO) useless top rail for the standard one.
Z