Lionel really didn't make very much Erie. You can look on EBAY, and specify Erie. If you see something you like, record the number(s) and price, and do some comparison shopping. There some Erie cars made by various O Gauge manufacturers such as MTH, Weaver, even some newer Lionel. Lionel was based in N NJ, so they did much more Lackawanna RR than Erie.
What I have/operate is old. Now they have more hi-tech stuff that can be controlled by a separate walk around controller and even a cell phone. It can be expensive, and it's too late for me to consider changing over, but there are a lot of more detailed engines and cars now, compared to when I was buying.