re: Where can I find back fat?

You may be looking for dehydrated pork skins, not back fat, for cracklins (the kind that comes in a bag like chips). Depends on the type of cracklin, maybe skin on belly instead of just the skin (the kind you buy at a cajun shop). If you deep fry straight back fat it will basically dissappear into the oil.

If this is what you intend Oak Point in Central sells pork back fat in the freezer section. Ask the butcher if you can't find it. The other items can be found in most asian or mexican markets, call first and ask.