I was thinking of making potato soup using pancetta and prosciutto, would that be any good?!

I really don't know - - I see these fine exotic sausage meats - but I am staggered at the cost for scraps and lesser quality meats

http://en.wikipedia.org/wiki/Pancetta

http://en.wikipedia.org/wiki/Prosciutto

I don't know about you but I've found a smoked breakfast ham that is wonderful in my soups and stews - just fine for dicing in bite size chunks
good luck

Mostly sounds good but can I make a few suggestions

1) Use pancetta and saute it in some butter (use butter for this soup) and then remove the crispy pancetta to use at serving time. (otherwise you cannot puree the soup with the pancetta in it)

2) Saute the finely chopped veggies in the butter flavored with the pancetta on low but don't brown. But, saute until wilted and soft. I would add onions, shallots or leeks to the vegetables (whatever you have available)

3) If you want fried onions (as in crispy onions), saute them now and drain on paper towels and serve with the pancetta as a topping for the soup.

4) Add the stock to the soup and cook until all the veggies are soft

5) Puree the soup in a blender or immersion blender in the pan (be careful)

6) Skip the mozzarella. It will be overkill for this recipe. But, you might want to consider adding a cup of cream to the pureed soup

Serve soup with reserved pancetta, crispy onions and optionally some croutons

Anything boiled with potatoes is going to make a nice thick soup. I would not put in cheese, that's going to make the soup gloopy. If you serve the soup hot, people can add their own cheese if they wish. You can put some grated or thinly cut cheese on a side plate for people to dump in their hot soup.

I don't really like carrots in soup, but onion are great. Celery is ok, it is kind of neutral. I do suggest that you use parsley. And a chopped green spice, such as oregano. Myself I use chopped mint, but that is not a popular flavour.

Oh dear sweet god where do you live? I'm coming over for dinner. lol