I like your enthusiasm. You will have the motivation to get plants started. Please see my advice in the post:
I recommend reading the book “The Fruit Gardener’s Bible” because the authors lived in cold climates, unlike most orchard books.
Some of those fruit that you mentioned will not work together, but you motivated me to try some combinations.
I dislike the idea of growing blackthorn aka sloe due to it being invasive and the thorns detaching causing chronic infections and requiring surgical removal. Seems like a public health hazard.
Sloe compote juice blended with seaberry works surprisingly well, so I would expect the right European plums as compote would work well in that position too.
