I imagine EuroRail website would have information about all sorts of Rail Pass.
The only thing I heard is in Italy You want to take first class train only because it is not safe on the second class (pickpockets, robbery, etc)
We did a driving trip around Europe, using campsites all the way. The whole trip took a bit over a month, not remember exactly how many days, may be 40 to 45. We covered 2/3 of Europe except Eastern Europe, Portugal and Greece.