Ok guys and gals, bought my lower awhile back. Order a 20 inch barrel kit. Had problems with the company so went out and bought a M4 style barrel that just changed everything about my plans on building my first Ar 15. I'm clueless on the M4 style Ar guns. So tell me what you would put on this gun. Planning on using it for fun doing scenario target shooting with friends. The scope was for the 20 inch barrel but not sure what type of sights to put on it since the barrel is so short and has a gas block where the front sight would be.