Oh, man... you're making me feel a bit dated.
When I was in Italy in 1982, I snagged my Colnago Super, and it wasn't that obsolete at the time. I think I only rode it on day trips with a backpack in Italy.
The next trip, 86/87, I bought another older road bike. The only rack I could find was a bent steel rack, which just didn't hold up. But, that bike did some extensive mini-tours around Italy.
At that time, there seemed to be a dichotomy between racers, and commuters, with very few in between.
Also, pre-internet, no just hopping on the internet and buying one's accessories elsewhere in Europe.
Anyway, consider a vintage classic steel road bike if you can find one, and it suits your needs. Bring some accessories with you, or plan on sourcing via internet if you can't find what you need.
Also, keep in mind that cycling isn't evenly distributed around Italy, or wasn't at that time. Lots of commuter cyclists in Parma and the Po Valley. Almost no bikes in Perugia.