Is there much difference using the Italian 00?

pasta is better when using semolina or a mixture with regular flour. Using normal all purpose or bread flour is ok but doesn't have the same texture. For a light noodle or mixed with pumpkin/spinach etc would be fine. I typically use 50/50 semolina and all purpose, it has a good texture, not as expensive and still retains a good strength.

00 flour makes the best pizza dough but not really pasta.

pasta is better when using semolina or a mixture with regular flour. Using normal all purpose or bread flour is ok but doesn't have the same texture. For a light noodle or mixed with pumpkin/spinach etc would be fine. I typically use 50/50 semolina and all purpose, it has a good texture, not as expensive and still retains a good strength.

00 flour makes the best pizza dough but not really pasta.

Actually, 00 flour just means that it's very white, or to put it another way, it has a very high rate of bran extraction. Italians classify flour (excepting semolina) by whiteness ranging from 00 to 04. It can vary very widely in protein content. i've seen different brands of 00 ranging from 4% protein up to 12 or 13 percent. So obviously there would be a big difference in results depending on what 00 flour you would use. I live in Chiang Mai and Yok baking supplies sells both finely ground and more coarsely ground semolina.I agree with zeichen that a adding semolina is a good idea. So is high protein 00 flour. A mixture of semolina and high protein 00 is what I prefer. That said, you can make really good pasta using just unbleached all purpose flour.which would have a protein content of around 10.5 to percent.

"Actually, 00 flour just means that it's very white"

Thanks, I didn't know that. I thought the 00 was all a high protein flour because that is the only ones that I have seen for sale and is what is used to make Pizza dough where I am from.