That LMT is an incredible rear sight, I know because I've cut down a couple carry handles to achieve the same thing. Tough as nails but heavy and of course doesn't fold down.
If you ever decide to try the IBZ or RIBZ it'll be a lot of fun. Good optics have reduced the interest in all this but if you like irons you have the right rear sight!
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek