To be honest removing the turbo probably wouldn't save much fuel.
For example, the non Turbo Fiat Coupe 20V does a similar MPG to the turbo version.
Also if you Look at the Alfa Mito, the non-turbo versions are not much more economical than the turbo versions.
IMO your best bet is to buy a TB, keep the turbo but fit an electronic boost controller. That way you can turn down maximum boost when you are in fuel saving mode.
A very light pressure turbo can actually be more economical than a non turbo. Because the turbo assists in filling the cylinders with air, and reduces the pumping losses by a large degree.
Giulietta 2.0JTDm (170)