I'm going to start with DC just in order to get things up and running as inexpensively as possible. Since none of my motive power which is weight restricted prototypically to the 4-4-0 wheel arrangement is available with RP-25 wheelsets I will have to kitbash-scratchbuild my motive power. With this in mind I am reasonably certain that I can mount a Digitrax decoder and 1" speaker in the tenders of both the Pennsy modern D-16, and a CNJ 4-4-0 Camelback. The two Baldwin generic modern 4-4-0's are somewhat problematic and may have to have some sort of mod. Would an N gauge decoder/spkr work? I don't know. The "Yellow Jacket" was a single vehicle verticle boiler steam powered inspection unit that was used to carry the mail, packages, and passengers to Barnegat City, known as Barnegat Light today.
At some point I want to be able to run the Pennsy "Seashore Express" from Camden to Beach Haven, stopping at Barnegat village to pick up CNJ passengers also bound for Beach Haven on Long Beach Island, NJ. This was the route that my grandparents took from NYC. In addition, the Tuckerton Rail Road will be running its regular mixed and freight service to Beach Haven and Barnegat City. In all, I expect that we could have something like 5 consists running similtaneousy.
Yeah, I have golden dreams on a copper budget! Oh Well! I can dream can't I?