Linux: We used rails similar to what your looking at on our AR's to mount lights when I was a Narc. They held up great to being banged around and from the recoil of the rifle.
No need to worry about heat. If it gets hot the hole gun will be hot from some extreme firing. The holes are pluged by the attaching screws and nuts.
You might look for a plain flat mount rail. You'll find when its mounted on either the left or right side of the handguard, it'll be out or the way of the sight. Hope this helped.