There are currently no strict requirements regarding the technology stack to be used. Ease of deployment is desirable, but even that could be traded for, for instance, faster development times.
I'm a big fan of old-school text user interfaces, like the ones we used to have with Clipper.
I'm of course aware of its many limitations, but, to the best of my knowledge, its simplicity is unmatched by more recent technologies. So I'm seriously considering building a POC consisting of a web-based client operating as a specialized dumb terminal (performing some app-specific functions, like report printing, besides its basic terminal stuff), accessing the TUI-based main application in the server side.
We believe it's going to be possible to detect most of the limitations of such approach with that proof-of-concept, but I also considered asking the community looking for other ideas and limitations I may be ignoring at the moment.