Giampaolo,
Let me know if you come up with a source for this Pouteria. I had also been looking for it without success. I had also been looking at Chileflora for seeds for this one & also Lardizabala -- however, if I recall correctly, their conditions of sale severely limited your use of the seeds. For example, you could not sell fruit from the your resulting trees. So, if you come up with anything, I'd appreciate it if you could pass the info along to me.
John