Various gas blocks you can install to get rid of the FSB, the FSB should knock off pretty easily. I am not a fan of cutting off good parts just to save time, but that's just me. Personally speaking I would knock off the FSB, get a mid length free float rail like the Daniel Defense MFR 12" or the Troy TRX and a low pro gas block. I'd then mount my flip up front sight all the way forward on the MFR/TRX. This setup is pretty much how I run my personal AR, but I put on a Burris 1-4x XTR w/o irons.

Like the previous poster said, rifle setup is a matter of personal preference, that's the beauty of the AR15 platform.