I don't have a source for you offhand, but I think it is one of the Prunus serrulata. Perhaps you can search by that.

Prunus serrulata is a wild species cherry, Sato Zakura (Japanese garden cherries) are now considered to be hybrids. The practice of listing this as forms of P. serrulata is obsolete.

P. 'Amanogawa' is common. Telephone your favorite garden center(s), they may now (or soon) even have one bareroot to sell you.