Hi Daen, firstly, welcome to the guild.
You might want to take a look at author Guy Gavriel Kay's work for inspiration. I'd highly recommend him to any fantasy reader anyway (he's probably my favourite fantasy author) but taking bits of Europe and putting a fantasy twist on them is pretty much what he does. So, for example, he's got Esperana for Spain, Sarantine/Byzantine, Cartada/Cordoba, Silvenes/Seville, Dubrava/Dubrovnik, Arabic/Asharite etc etc. I think Ladiestorm's got the right idea above. Just swap some letters from an existing place around till you've got something distinct. I'm not sure if you want people to have the impression of real world places as they read your book? You probably don't want names to be too similar unless you're deliberately invoking thoughts of the real place.
As for an Italy-shaped substitute, well, frankly, use your imagination! It's fantasy. You can have anything you want.
What would work within your story? How can you develop the shape of the land as an element of the book? What does the story need? Start from there and see what develops.