I don't think there is much in the way of duplicating films that are either affordable, or still manufactured.
I used to do quite a lot of duplicating of 4x5 film in a pro lab. We had two versions for our customers, one version was very expensive and we used a Kodak cut sheet film designed for duplicating, this was for top end jobs and clients with money.
The other method, is one I use still in my own darkroom. I just use Tmax 100 which by the way has an expiry date of 1991 on the outside of the 100 sheet box.
This method isn't exactly great, but it isn't too bad either. Basically I take a sheet of film and give it a pre-flash of exposure under the enlarger. I sit it in a special easel which is blacked out completely, instead of white or yellow to do this.
Next I take the neg that is going to be duped and place it emulsion to emulsion with the other sheet. Place a sheet of glass with anti newton etching on top, then make an exposure.
The neg is then developed as per usual to a time that has been worked out with empirical methods.
Now of course you end up with a transparency by doing this, so you repeat the method again and you end up with a workable negative, which is a reasonable facsimile of the original.
I'm not saying it's perfect but I copied an archive of 20 odd negatives from WWII for making prints from as the original negs were quite frail. The resulting 8x10" prints were more than adequate.
You could use ortho litho film too, couldn't you? It's suppose to be very very fine grain. Just develop it in paper developer for continuous tones instead of lith two-tone effect. It's less hassle than working with panchromatic film (speaking from experience of enlarged negatives).
this is pretty much the same as kodak's professional duplicating film.
it is very slow, like azo paper, and requires a bright light to expose.
it will yield a negative from a negative ( single step ).
it processes in print developer.
the better way to work with this film is to use Cold light ( the old blue one) comparing my tungsten enlarger light vs cold light give me a 6/1 ratio. When I need 60 sec with my tung light I just need 10 sec with my cold light.