More AR15 Questions
My 2 cents: S&W offers melonited barrels. These tested better than some chrome for wear protection. RRA offers chrome lined barrels as an option. Both are good rifles.
Go with a mid-length gas system. You get a more gentle recoil and can have a longer rail for better gripping. PSA offers those as well as others such as Daniel Defense.
Use quality folding iron sights and maybe a red dot or 1x4 scope to start.
Make sure the receiver extension mild pec so long term it is cheaper to upgrade the stock (and you will have more options).