Originally Posted by HarryT
Is the iPod sold in Portugal? If so, you'll be able to access the iTunes store; it's the same store.
I'm not sure about the warranty question; you might well have to return it to the UK or Spain if it went wrong (I imagine Spain would be a lot easier for you). But iPads seem pretty reliable - I honestly can't remember seeing anyone here report problems.
I've read somewhere, wherever you purchase your iPad, it's under Apple's warranty in your country of residence. Not so for the iPhone4.