For the legal side of things, here's a
good resource on laws regarding keeping, collecting, and breeding reptiles and amphibians in every state. In KY you'd need a captive wildlife permit ($75/3 years) to keep more than 5 individuals of any species native to the state (so, all of the species you listed except I. bellii). Even with that permit, you can only legally collect from Kentucky up to 5 individuals of each of those species--beyond those 5, any other individuals in your collection would need to be captive-bred with documentation that you bred them, or with a receipt from the seller if you bought or traded them. You're not allowed to collect on Kentucky Dept. of Fish & Wildlife-managed land. For all species, but A. aeneus especially, I'd strongly recommend buying captive-bred.
Indoor Ecosystems, a company run by a member here, had captive-bred A. aeneus the last time I checked. I bought several salamanders of another species from them this past year and they're all thriving.
Caudata Culture has caresheets for keeping and breeding P. cinereus and E. cirrigera; I'd highly recommend checking those out as a starting point!
Most importantly, do *a lot* of research before jumping in on this. Plethodontids aren't easy to keep, and they're harder to breed--all are sensitive to a wide range of environmental factors, and many (particularly those in the P. cinereus and E. bislineata/cirrigera complexes) are quite territorial. Visit where they live and take notes, getting familiar with the abiotic factors of their microhabitats (moisture levels, rock types, water movement as applicable, etc). If you're planning to use more complex setups (especially if they'll have custom backgrounds and/or be bioactive), build them well in advance so you can make sure all the parameters are stable before adding the inhabitants.
