Subaru Legacy and Outback. What's the main difference?

[TypeR]

I'm looking for a used estate car. Budget approx £7,000. The Outback appeals, but a Legacy will probably do as well. I realise the Outback has a higher ride height than the Leagacy, but apart from that, what are the major differences?
I've decided to go with the petrol engined versions, the 3 litre six seems to have enough poke to keep me amused. Any pros or cons?