It is a myth that bigger displacement engines use more fuel. 1.3 will not be underpowered and will have a better fuel economy. Have experienced it first hand.
If you want to swap, I would recommend you to buy a nose-cut, use the parts you need and sell the rest. Because when you go to swap a bigger engine, you will need change the suspension and brake components as well. Otherwise the car will be ill-balanced and might turn over on corners at high speed.
