Privacy planting

Hi. We are in the process of clearing a large area of our garden that used to be a massive rhododendron bush, probably 20 ft plus high. This used to continue into our neighbours garden as well but he has cleared his already and a 6ft fence was erected a couple of weeks ago. Either side of where the rhododendron was are some high leylandii.

The problem is that we will have a wide gap of about 30ft between the remaining leylandii and the relative heights of the houses means that even with the fence, there will be a privacy issue, so my idea is to plant something(s) that will end up being at least as high as the old rhododendron.

We would like to create a patio in the reclaimed area, so just putting in some more firs has the disadvantage that the width at the bottom will take up a lot of our new area, slightly defeating the object of the exercise.

I am therefore very interested in pleached trees and saw some pleached Photinia at a local garden centre. The bare stems would give us plenty of room and as long as the leaves start level with the top of the fence, would give us the necessary privacy.

So, is Photinia a suitable choice in a south facing area, will it grow up to 20ft and are there some other pleached options that we might consider?

Thank you for any thoughts.