Why would they sell you anything you don't want if your husband is a gun guy, just have him go with you.

16 in barrel rifle is the shortest by law without the stamp.

You can get a pistol AR with a pistol brace, with shorter barrels. Check your local laws before purchase.

Go to the AR15 website and educate yourself, then just go get entry level PSA, S&W, RRA or the Armalite if oz matter than much and be done with it. Don't overthink the purchase, and if you do, just get an LMT and be then you can really be done with it.