Do you mean a standard? I've not seen one grown as a standard but am in the process of making a pair from cuttings. Its a long slow business though! If you have the patience you could beg a nice long cutting from someone (they are quite common) and root it yourself. Sorry can't suggest a US supplier though.

if you put the request into your search engine it should come up with suppliers for you in the USA.

Welcome to GoY too.

Call your local independent garden centers--those not attached to a "big box store". If they don't have one, they might be able to order one for you.