Build help

I'm building an AR from the ground up but can't figure out what type of rail will achieve the look I'm trying to go for. This lower is from shadow ops which has its own compete story. (23 month delivery). I will be ordering something like this for my upper. I like the hard lines but don't want the engraving that they have on this one.

I'm looking for a rail that is between 13"-15". I have looked a troy, geissele, MI, and diamond head without any luck. I will only need to attach a bi-pod to the rail and it needs to be free float. I'm looking for something that follows the same theme of hard lines and weight isn't a worry. This will not be a gun that I take into the woods.

I know you guys will bring something to my attention that I haven't seen before.