Hi Antonio - Liverpool and Manchester are relatively cheap, Oxford and Cambridge expensive. In general, the South of the UK is more expensive than the north, especially around London. Liverpool and Manchester both have airports with good connections to Spain (EasyJet fly Liverpool-Madrid everyday). I'm afraid I don't know much about getting work in the computer industry, though I'm always reading that there are shortages. However, it's likely that these are in London and the south!

Saludos.