I am familiar with juniper berries being used to flavour gin but not as edible fruits. The only ones that I have seen have had very hard and small crunchy berries - not something that I would consider eating.

The species that is used commercially is the circumpolar species Juniperus communis. I remember reading that the best flavoured "berries" (modified cones) develop on trees growing in hot, dry situations such as southern Europe and the Middle east.

Don't know if there are varieties out there grown for their fruits but there are several named forms grown for ornament.