This will suit your needs well. Even though it is Armalite brand, it will do what you need. It appears to be in stock at the moment. If it is not, call them on the phone. They will frequently make a kit if you ask.
https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01&ReturnURL=/Armalite/Product-Category/AR10-Parts-Accessories/Lower-Receiver-Parts&Category=ac614400-ff09-4cdf-9d35-419a654e7201