Tobacco is always what the hydroshop here uses in their demo grows.
I've grown it a couple times just for an ornamental. It's flowers are quite a show. Very ez to grow and can get huge.
I've seen seeds sold almost everywhere...garden stores, grocery store, etsy, ebay, Park Seed etc.
I wouldn't know the first step to get it from live plant to rolled cigar or cigarette though. I tried to use a few leaves as a blunt wrap, just winging it and not knowing what I was doing, and it didn't go well. Winter killed my plants and I never started more but have been thinking about it