Well, I've done it. Adios Railking. I'm going 3RS and just got my first piece of rolling stock in, a K-Line Superliner II Sleeper. In order to keep my Amtrak trains interesting, I was curious if anyone knew of any private railcars that are readily available to purchase as 3RS models. I know of 4 so far: 1937 Super Chief Lounge Acoma by GGD, 20th Century Limited Observation Hickory Creek by GGD, and Silver Lariat and Silver Solarium by Atlas O. The one problem is that I've been having some difficulty finding Hickory Creek, Silver Solarium, and Acoma. Region-specific cars don't matter too much as almost all Superliner-equipped trains are the same (+/- 1 or 2 cars). The only thing that does matter is that the car in real life is Amtrak-certified and has been behind an Amtrak train at least once.
If you're thinking of referring me to Beth at the Public Delivery Track, I've already talked to her a bit and she only has Silver Lariat.
As always, I really appreciate everyone's advice.