I don't find any information it is commercially available in the US. Your best bet is likely going to be obtaining cuttings from someone who grows it and either rooting them yourself; having someone proficient at rooting them do it for you; or contacting Steve Singer at Wisconsin Roses and arrange to have bud wood sent from someone who grows it to him at the appropriate time for him to bud it to multiflora stock for you. Own root, where it's happy, it gets tall. Budded, and happy, it's virtually a climber.
