3lbs is the norm. The more bees you have up front, the faster the foundation can be drawn out and the queen can be most productive.
As Ryan stated, you need more equipment than a nuc, they will quickly outgrow that.
Most folks do not recommend starting with less than 2 colonies. That way you have the ability to compare, and take from one to help the other if needed.
Italians are fine. If at a later date you want to change, you can just requeen with a different breed.