pacific rose apples
This is the sort of request I would take to the Santa Monica Farmers market and make sure to talk with Michael Cirone of Cirone Farms. They have grown some 70 varieties of apples. If you google him I believe that you'll end up finding a listing on Facebook for See Canyon Farms and you can ask that way as well.
Curious to know what is Pacific rose apples. Is it the kind found in tropical regions like Hawaii or Taiwan? It's not an "apple" but a sweet non-fleshy fruit related to what we call "mountain apples" (sygyzium jambos?), which is fleshy, found in remote areas of the rain forests in Hawaii. I've also seen "rose apple" plants for sale at Asian supermarket malls and at 99 Ranch Markets occasionally. The fruit kind of resembles a jujube and not too common here in LA. I know it grows here since I've had mine for several years. I have never seen the fruit sold here commercially. Good luck.
17713 Pioneer Blvd, Artesia, CA