Al's link looks good. I didn't read it in detail so I may be a little repetitive here. For the soup that you're making, I would use a potato gnocchi. I prefer to use potato with cream sauces, pesto sauces and meats (rabbit, beef, etc). For a red sauce or a lighter dish with maybe just olive oil, tomato and basil, I like to make a ricotta gnocchi.
I worked with a great Italian chef a few years back and got to make a lot of potato gnocchi. It's not as hard as some people make it out to be. Just work as quickly as possible when the potatoes come out of the oven. Peel them and put them through the ricer while they are still hot. Add your egg, salt, pepper, and start folding in the flour while still hot.
Good luck