Your bacon won't be red, but more greyish in colour due to oxydation, and the taste is a bit different, but not much. The most obvious difference is the grey colour of the meat.
Pork belly cures just fine without nitrites, as I define the word. I'm not sure what Jon Des means when he says that it does not cure.
Due to EU regulations nitrites can be used again.
YOu can get pink salt at William-sooma, pricey,but it lasts a long time.