Okay. I'm thinking of another AR and am leaning towards a second RRA "entry tactical" or maybe a Stag "model #1". Here are my questions. I'd like to install a 9 or 10" free-float quad rail on whatever I end up getting. I'd also like to either swap the standard front sight for a low profile gas block.....or cut down the front sight (if possible). Having never done this type of procedure, what are my options and what's the difficulty? Once I remove the standard hand guard what else has to be done? I guess I'm wondering how the free-float modular rail attaches to the upper. Also...will a permanently attached muzzle brake cause a problem for installation? Sorry if this is kind of scatter brained (I'm tired)....and thanks for any advice.