The only place you might be able to order a new 1.4L FIRE engine from would be an FCA dealership, and even then I'm not 100% sure. They're definitely going to charge you more than you want to pay, and you may have to wait through a geological era for it to be built and ship from Italy, but it might be possible. A better choice would be to find a wrecked car with the 1.4L FIRE engine and pull it (every Fiat 500 uses this engine, though most aren't turbocharged). They should all be the same mechanically.