guero6371
Hello & Welcome to the Forum!
If you will follow the link and go to page 44 of the pdf, you'll be able to use the table located on the page to figure out you power requirement needs.
http://www.slsprr.net/history/1954LionelTrainsAccess.pdfOnce you figure out how much power you'll need to operate your trains & accessories have and take into consideration any possible future power requirements, you can decide on a transformer to meet your power needs.
Happy Rails.
Dave