New AR build

I've been planning on building a AR-15 gun from scratch for a year or so. I'd been back and forth on the configuration, but it boiled down to a lightweight build. I was torn between a pistol or a carbine. I had also planned on doing it all myself, buying a stripped lower and upper, and all the parts and putting it together as a fun project.
However, I stopped in at a new gun store locally, and they were selling a full lower, very lightweight, for a great price. Then the search was on to get an upper for it. I have a Bushmaster A1 upper in the safe, but I wanted something more modern and lighter. I put together a recipe for the ideal lightweight upper, but it's hard to find these ideal parts all the time, and there was one part/combo I couldn't deal with: a 14.5" barrel with permanently attached muzzle device taking it to 16". I can't legally own a 14.5" barrel, and I didn't want to torque the barrel into the receiver. My plan was to have a local gunsmith do it for me.
In the meantime, I kept surfing all the manufacturer web sites looking for an upper that was close to my recipe, affordable, and in stock. I found one at Loki Weapon Systems, with their LWS STD upper. I chose a 16" barrel with A2 flash hider so I could exchange it for the Yankee Hill model I wanted. It has a 1 in 8" twist barrel. I wanted 1:7, but this will work.

It arrived yesterday, and I'm happy. I was expecting a thinner barrel, but it's still lighter than my Bushmaster upper, has a free float barrel system. The gas block rail is lower than the receiver, I'm wondering if my front sight will be too low.