I am wanting to use duratrans but the company I wanted to use that totes 4000dpi says they can't offer the oversized (larger than 48") because Kodak stopped making it.
Only one digital photo machine images to the width you're looking for and that is a Lightjet 500XL using 72 inch width (and smaller) media. Durst Lambdas were limited to 50 inch width materials. The machine prints@200 and 300ppi. 4000dpi was only sales-speak from Lightjet.
If Kodak no longer offers the Duratrans in that size, contact Barney Tong at FujiFilm in Cypress, CA. to learn if Fujitrans is available in 72 inch width from them. Barney will also know who / where any Lightjet XLs are still in service. The shop would still need their 80 inch chemical processor and their 80 laminator in service as well.
Another source for current inkjet technology Duratrans as a substitute (coincidentally also in Cypress, CA.) is Scott Powers at D'Andrea Visual Comm. Be sure to stress the importance of your "high-end" customer's expectations.
Good luck and try to report back with what you find. Clients are weirdly trending asking for true Duratrans again. I'm not sure where this stems.
PS: Know that I'm not affiliated with the sources mentioned above.