I would suggest getting a low profile rail, like Troy. The YHM, MTG, and others are way to large IMO. My father put a YHM rail on a build last year and it's so big it feels like an Aresol can is mounted to his gun.
A small profile Troy runs around 160, and you can get a low profile gas block and have the rail cover it if you want it to look cool.
I received my 14.5" Palmetto Upper and I am going to put a low profile GB with Troy rail. It will be extremely light weight and usable.
The 14.5 is noticably shorter than my other two 16" AR's. I love it.