Get two different varieties of plum on one tree!
Plum Black Doris are an excellent all purpose variety. Produces medium sized fruit with purple-black skin and sweet, dark red, juicy flesh. A vigorous tree with an upright growth habit and they are a mid-season variety.
Plum Omega is another good all-rounder that produces good crops of medium sized fruit with red-speckled skin and deep red, juicy flesh. These are a late season variety that are partially self-fertile.
Plant in a sunny position where soils are fertile and free-draining. Ensure that they have adequate water during the growing season and when in fruit. Prune as required.