advice on slender upright small tree please

[traviata]

Very small space available, but I need screening. Bare branches will be sufficient, just to break up the sightlines, so I'm looking at a deciduous tree.
I've already got a crab apple and an apple and a magnolia.

The soil is clay and this corner does get a bit soggy in winter, but I could mound plant.

I need a bare stem up to 7' tall (to access the shed) and a spread of max 4m. Total height 4-20m.

The chief thing is to have something slender and upright.
My shortlist is:

Amelanchier arborea Robin Hill
Prunus Sargentii Rancho Tree
Prunus subhirtella Autumnalis Rosea Cherry Tree

Any thoughts?

I'd never realised acers could grow tall and thin, all of mine are like bushes.

Arsey - everything looks random when things are tiny! You wait, it will be Heligan meets Babylon in the blink of an eye!!

traviata - your combination sounds impeccably tasteful! I think we should make a 'ban all garish primulas' campaign. I hear you on the propagation, that's what I'm doing too. My resolution this year is to pot seedlings on at the right time and not leave them too long!

traviata, have you considered a Prunus Pandora? They're a lovely upswept shape.

Pandora is v pretty but it looks as though I'd have difficulty in getting the clear trunk I need.

I think Amelanchier Robin Hill has it.

I bought 2 Amelanchier Robin Hill from Barcham Trees. They were excellent great customer service. They supplied really good stakes, soil and bark with them . They are the biggest feature in my new garden and they look stunning.

I'm thinking of getting one now! It would be to plant about 6 feet in front of a window, do you think the habit would be airy enough?

Arsey I haven't got my tree yet, but I note that the Amelanchier is described as a 'dense' small tree on the websites.

The winter flowering cherry Prunus subhirtella is always described as having really delicate twigs, so this might be a more airy option.

Hopefully someone experienced can comment!

My Amelanchier trunks are a bare 10feet then the branches are open goblet shaped another 5. Feet. If you buy from a specialist nursery you can choose the shape of tree. . I really wanted a skinny tall trees with lighter canopy. I have seen them in our local cemetery in all different forms.

At this time of year I am loving my winter flowering cherry. It really perks up a dead time.

oh now I want a winter cherry as well.

I am going to get a winter cherry next winter, and plant it near my house so I can really enjoy it. I marvel at how a plant can be both so delicate in appearance yet so tough as to flower in the worst of weather. There's something to aspire to in life, I think!!

Early morning philosophy. I love these garden threads. Morning all.

I have a winter cherry. As they grow older they spread a bit, which could cause problems for my path I think, if I planted one where I'm thinking of putting the Amelanchier.

Hhm. I've also seen Amelanchier described as both dense and a good replacement for net curtains as they let in plenty of light. Most confusing!