I've got a little red book from the RHS. Its called the plant finder and it's got sections for different garden/soil conditions and plants that would suit. I can't find it though!!! No help at all but if you went on the RHS website I'm sure you'll find something on there. Happy birthday from me! x
Acers good in pots but they dont like the wind. I dont think a Magnolia is ideal for a pot in a windy situation, they are really woodland shrubs/trees. Escallonias and Hebes are both good suggestions as they take the wind and the flowers are pretty too.
Magnolias can do fine in windy areas if they are planted sheltered from the wind. We have hurricane force winds that come in from the west but I've seen magnolias do very well when given enough shelter on the east side of homes in the area.