Dear geeks, part two- aka I need a new computer

 So, Ari and I have a laptop each, theoretically. But they are both terrible - they crash, they burn, they freeze, they die.

As we have a little bit of spare cash right now, we're on the lookout for a new one. Particularly as said money is being earn by using the computers, and using one that works woudl make us about more efficient, which = more time to drink gin.

I know that a lot of our friends are very on top of what's hot, and good deals, and also know people who might be selling off used ones. If we want a used one, we do want one that's of decent quality - we've been through a raft of cast offs that have shortly died, but we are prepared to pay for that.

We really don't want to spend more than £400 though. Andy has sent us a link to a quite good looking one for £369, so it's doable. I suppose we just didn't want someone to say 'oh, hey, my friend just sold his really good one for £200' (people have in the past when we haven't had that much)

Our needs are in essence fairly basic. Needs to run fast and be sturdy:

Mac or PC - don't care
Weight - not too bothered - generally for home use
Memory - fairly high would be good, storage wise and the other type of memory (RAM?)
Hardiness - v important. Needs to be trampleable on by a cat and spillable upon by the odd bit of chinese food.
Battery power - any kind would be a new and unchartered experience for us!
Fancy features - not sure it needs any.

Any tips or leads greatly appreciated. We're not in a massive hurry, so want to keep an eye out and exploit opportunities.

Thanks

Lizzie