Ask HN: Oscilloscope for Modern PCB Busses?

I am working on a team to bring up and debug a new carrier board design for an Nvidia Jetson NX module. Presently, we are having occasional trouble with some of the differential busses (e.g. USB, PCIe, ethernet), so we want to probe and analyze the signals.

Our current electronics bench equipment is not up for the task of working with modern high speed busses, so I am researching our options for upgrading our scope (to start). Given the frequencies involved, the options seem limited to the high end models.

What specifications would you require for this kind of work? What brands/models should we consider? When we are ready to buy, where can we find good deals?