I grow san marzanos in my garden so i used my own in the recipe, it was about 7lbs total. Also I do not eat pork, so I used a thick cut "turkey bacon" in this recipe. As for the pepperoncinis, if you use the pre-sliced ones you are going to get A LOT more than if you use the whole ones. I used a whole jar of the whole pepperoncinis, and could barely detect any heat or spice. Also make sure you use yellow onions for their sweetness.
The sauce is decent, I deglazed the pan with a little white wine as suggested, after adding the onions. It still needed more sweetness so I added about a tablespoon of sugar which seemed to help. But it is still missing something, herbs maybe. I will add them next time, and use wheat pasta it seems that would be the best pasta for this type of sauce to contrast with the flavors.