As others have said, there are options. I decided to get the Corbin 1400 touring for my bike (around $550)plus their driver backrest ($250 approx), and the Hepco becker Cali 1400 touring back rest and rack ($450). There is a guzzi shop in Texas, AF1racing that sells the 2017 California Touring rack with backrest for about $1,000. There is another shop I think in Cincinnati that had the same thing for less. In the end, the Hepco was cheaper, Moto Machines is the importer, and it is really a nice unit, really stout, the rack is big enough to be functional.
I am excited to get the Corbin and try it. I am pondering buying a used stock Touring seat, there is someone on here that is thinking of selling a used one, PM if interested and I will give you his name.