Is it legal for my wife and I to make porn in our home in AR and sell it on the internet?

So long as you and your wife are of legal age, you can film anything you please that does not violate state or Federal law. As far as selling the video on the Internet, you also need to make sure that your video does not violate the laws of any city/state/country where the video can be bought and viewed. That could be an extremely tedious process to find out the laws of each city/state/country where it is to be sold for viewing.