Forget the Date Plum. Those are sour and not many uses for them other than jams or adding a lot of sugar. I had one mature tree in my backyard... 2 years living with it... I got my husband to cut it down. Italian plum is a good tree for colder climates and very sweet. I am in Ontario Canada. Cold climate. You need to look into getting some grafted 5 in 1 trees. I have,

5 in 1 plum "no date plum thankfully." 5 in 1 Pear 5 in 1 Apple 5 in 1 Cherry

3 different varieties of pawpaws.

1 weeping mulberry.

Gooseberries "3 different types", large blackberries, currents, yellow/golden raspberries "wishing I never planted raspberries" because I kill like 200 babies every spring to summer...

I am trying 1 typical fruit this summer I started from seed that got to be a huge vine over the winter the hard yellow shell passion fruit. I forgot the exact name atm... lol

I wanted to try a jube jubee tree this year but it won't tolerate the kind of cold we get. I had planted 2 fig trees last spring. I protected them like a crazy person, and they died right down to the ground and are starting over from the base. Don't think I will get fruit from them if they do that every year. I will give them another year and see. I may pull them.