Can anyone make any recommendations - we are in southern Oz??

I have considered a luma apiculata and the acema smithii and a number of others but at this stage I'm not sure - I don't really want to get up on a ladder and prune the tops of 160 metres of hedge so something that would stop at about 3 metres in height would ideal. We are not big fans of pittosporum and like darker foilage.

The large, dark green shiny leaves are very attractive. It has upright spikes of tiny strongly scented ivory flowers in spring, followed by purplish black berries. It's a bit shy of flowering if exposed to wind.

There are some very attractive mature plantings in the Southern Highlands area of NSW.

The new growth (leaves and stems) ranges from light olive green to bright pink, depending on the variety, while the mature leaves are mid green - very attractive but not what I would refer to as "darker foliage".

Another suggestion would by myrtus communis (the common myrtle from the Mediteraean). This forms a dense, rounded shrub with small dark green leaves. Its very pretty small white flowers are followed by bluish black berries. I've put in a link with a photo.

Cherry laurel, photonia and the myrtle are all drought resistant once established, are frost hardy, provide dense foliage to the ground, and grow into a nice form without the need for pruning.

I understand your point regarding pruning - I used to have a tall cotoneaster hedge as the side of a driveway. It was only about 5 metres in length - why hasn't someone invented a self levelling ladder? - and had to be pruned from both sides. And, if you are aiming for 3 metres, you won't reach the top of the plant on a 6ft ladder - I know from experience that the taller the ladder, the more unstable they are.

Both the cherry laurel and the myrtle seem to easily strike from cuttings (that is, I've been successful).

The Bhutan Cypress will provide an excellent screen BUT Bourke's Backyard describes them as "fast-growing, cylindrical-shaped trees to a height of about 7-8m (20-24') in six years". That's a lot of pruning!

I think that when people "hear" hedge, they "see" a neatly pruned and shaped hedge and give little thought to the commitment required to maintain the neat shape. One of the purposes of pruning is to encourage new growth so the more one prunes, the more one has to prune.

There are a number of plants commonly used in pruned hedges which, if left to grow unpruned, develop into attractive trees or shrubs. But they are going to do it at a slower, more relaxed rate than their pruned relatives.

It's also worth remembering that most plants generally put on a bit of a growth spurt in their earliest years and then settle down to a more sedate growth pattern. I have a couple of bay trees which will ultimately grow huge, but not in my lifetime!! Now there's a thought - 160 metres of incoming producing hedge. As a bonus you get dense, dark green foliage to the ground.

Other considerations would be water requirements (are they going to need watering once they are established or are they fairly drought resistent) and are they prone to insect damage - for example, virburnum tinus, a popular hedge or screen choice, is more susceptible to red spider when it is planted in numbers.

Do you have those there?

It is a case of weighing up the pros and cons. Work out your priorities. How soon do you want the hedge to reach 3 metres? The budget will also come into it, as some plants cost more than others. After all, 160 metres is a lot of hedge. There have been a number of good suggestions so I will not add to them but you should consider the growth habit and your time factor. Check out the hedges in your area.