It's not like Italians don't wear jeans but last time I was there they were wearing really tight ones tucked into tall flat heeled boots, probably out of style by now. You can get some really comfortable black pants at Express that aren't pricey. I pack light and two weeks is exactly the same as one week so for myself I would take things that would only require like two pairs of shoes, a dress up pair and and walking pair. Black is easiest to match for me. I would feel out of place wearing sneaks and jeans myself, but then, I'm self conscious. If you're not - go for comfort only. I take one black textile car length water resistant coat/jacket and layer underneath for the weather. A nice scarf always comes in handy but you can buy them anywhere there. What time of year are you going?