Wanting Berries!

hchessom

Will Cotoneaster produce a lot of berries put against an East facing fence or a pyracanth shrub, also which is better to keep in shape. We are starting a small 12ft.x4ft. plot and it will be at one end. It is also a bit of a frost pocket.

Fairygirl

Yes is the short answer, as both will be fine, but it depends what variety you choose and what you mean by keeping in shape.
Both can be pruned whenever needed. Some cotoneasters are more horizontal ,some aren't evergreen etc. Some Pyracanthas are columnar, most aren't.

Frost doesn't affect any of them. 

raisingirl

Cotoneasters can get huge and untidy. Pyracantha is absolutely vicious. Both are beautiful - which works best depends on how much room there is (you don't want to be brushing past a pyracantha), whether you have time and inclination to keep it pruned and trimmed and, as FG said, which variety you chose