Peter Schneider, at Freedom Gardens, grows a number of Tantau roses, though I don't know if this is among them. He may be able to custom-propagate it for you, perhaps?
There's an Italian company that ships bareroot roses to the US which has it. The website is en.roses.it. You have to email them to set up the shipment, but I know someone who has ordered from them and said they were very accommodating and easy to work with.
Nope! That company “tried” to ship to the US, but Customs has shut them down now. 6 shipments got confiscated in Cincinnati last week. (Ask me how I know, lol!)