i would get the sights first. What barrel length do you have and what are your intentions for it? Ive got several for different purposes and the purposes determines my sight/optic configuration as well as a couple of other things like "cowitness". With my 2 precision builds one has MBUS Pro flip sights paired with a leupold optic. After sighting in my optic I barely ever use my BUS's unless its to make sure that they are still dialed in. the other precision has the same optic and canted sights. Both of those rifles are 20". My SBR and suppressed 16" both have the standard front iron post. The SBR has an aimpoint T1 with aimpoint magnifier with swing mount for CQB and the other has a trijicon acog on her. I firmly believe that with a rifle that you will be using for CQB that a front post is necessary in case optic failure (rare but not unheard of) that you way you can aquire the threat and eliminate. my rear sight on my SBR and 16" are the mbus pros that are quick to deploy. But nothing beats "point and shoot" in a cqb situation. Sights dont make you a better shooter; discipline, training, and muscle memory make you a better shooter.
But as the others have said, save your money for a good optic rather then spend that money on cheap optics. Leupold, Aimpoint, Eotech, Trijicon... great proven brands. If you have an eye problem then thats another problem all in itself but stay away from red dots if that is the case.
Hope this helps.
1999 Ford Mustang SVT Cobra Built
2011 Ford Taurus SHO TT AWD
he spent all the time
thinking about if it could be done, and not thinking about if it should be done