I'd advise anyone from buying outside their native country. You will get stiffed a lot on import duty. Oh, and any warranties will probably not be valid (and your household insurance may use it to wiggle out of any accidents it's covered for, too) and you really want a warranty on a laptop as when they go wrong, they go wrong expensively.
I buy Apple myself. The new MacBooks are amazing for the price and you can run MacOSX or Windows or even both.
If Apple are outside your budget, I'd steer clear of Vista, which means if you're buying a laptop with OEM Windows, you want a Dell loaded with XP. It's really that simple.