I have built a lower for a different build, just waiting on the upper to get here. So, now I am going to build an upper. I have the stripped upper, Thanks to Spitty. I am looking to build this on a budget. This will be for mainly target shooting probably no more than 200 yards. I am building it for the wife. Would like to go either 18" or 20" haven't decided fully, that is why I am asking for some choices. What twist rate? Chrome? Or other thing I need to know and look for and where to look for best deals. Thanks.