As soon as you plant two evergreens on a boundary you legally have a hedge and so you will need to be mindful of the high hedges legislation, which considers the 'reasonable enjoyment' of a property or garden, not just whether light is affected.

And surely something that is ten feet tall must cast shade at some point during the day?

Don't forget that conifers of that size won't stay at 10', so make sure you get prunable trees and steer clear of the dreaded Leylandii!!!!!!!

Have you thought of bamboos rather than conifers, which would have to be constrained to stop them 'walking' but are a delight in my garden. They have movement as well as being evergreen.

A rangeof berry bearing shrubs would be nice to encourage wildlife, interesting for you too
I 'm thinking pyracantha and cotoneaster for examples, the latter only semievergreen.....

Italian Cypress come to my mind. They are good looking and are well behaved and are light rather than dense foliage. There is a similar looking, more hardy, tree whose name I forget, which gives you the same look.

That'll be quite a dry area - I'd recommend Berberis darwinii (8 feet), Mahonia japonica (10 feet) and maybe Escallonia - choose 'Donard Seedling' or 'C. F. Ball', those two get to 10 feet, but Escallonia prefers a sunny spot. You will need to irrigate during dry spells, particularly for the first couple of years.

Photinia [red robin] and they trim easily to shape or shorten. I have a Potuguese Laurel which we keep at around 8 ft by trimming.Choisya Ternata [the Mexican Orange Blossom]. These are easy to maintain, attractive and evergreen.

Birch are shallow rooted which may be a problem?