Personally i use cheap lidl guanciale and parmiggiano, and also add some chili flakes and garlic. The only rule you should really ever adhere to is not to use cream or the jarred stuff.

Carbonara was created in the 40s after the war from american rations (allegedly). Who cares if you use pancetta or guanciale, pecorino or parmiggiano, just understand that you need to nicely emulsify the egg cheese mixture with the pasta and pasta water at a low temperature to get that creamy sauce.