Sorbus for autumn coloured leaves and red berries (they don't seem to like the white ones so much). We have just had waxwings visit our cotoneaster and holly berries are popular with the birds.

I was going to suggest Cotoneaster and Holly just as Bulba has.
I have a holly hedge (Ilex JC Van Tol) the non prickly variety - berries are popular and it also provides cover/safety for them.

then there is skimmia and acuba but you will need to make sure you get the female form and perhaps have a male form nearby. Skimmia rubella has both male and female parts so is self fertile.

I think I have a form of holly amongst the overgrowth, but it definitely hasn't porduced berries this year. I'll investigate the leaves more closely in a few days to see what it is. But then again, I think that the soil has so few nutrients in it that I'm surprised it's still living.

Thank you so much for the suggestions. My garden centre has a 50% off sale so I'll have to go and see if any of them are in that.