For 16g, I would hit up JusMX141 and see if he has one for sale and for FMIC I would go with https://www.rtmracing.com/xcart/product.php?productid=21633.
If you decide to go with a 20G I would go with an MHI oem 20G not that China 20G from that link.Yes, you would need that j pipe and 2g install kit and you’ll be good to go.