I guess I'm surprised they aren't a now popular genre to produce with current technology. I'm new to the hobby, but it seems there are some streamlined diesels (EMD,E and F series, 40s and 50s stuff), but not many steam variants produced. The new stuff is kind of cool in it's own right, but lacks the class of your streamliners. The ones that are out there seem to be made it unobtanium and out if reach for anyone who isn't a serious collector that's independently wealthy.
MTH re-popped some of the older stuff like the M1000. They even made the very cool tinplate monorail. 11-6060-0 | MTH ELECTRIC TRAINS You can get the older stuff pretty cheap, just dont fall into the ebay trap.
I bought my original M1000 at a show in tampa for $200, nice and running, original finish. Stick with Lionel
and MFG's that are still producing parts.