Euro cardstock, weights and amount

Hi all,

I have a friend of mine who will be returning to the States from Italy this Spring.
I have asked if she could bring some cardstock back, in A4 and maybe in A3 sizes

Now my question to my European friends, what are the common weights, and how many sheets to a pack do they come?

And for those in Italy, could you name a few places where one could get those packs of paper

Thanks in advance

Rick