The 146 Electronic Engine Display (two fitted side by side) are the same as that of the RJ. The Pilot Flight Display (PFD) and the Navigation Display(ND) fitted to many 146-300 and late 146-200 types/variants as standard are not the same as those fitted to the RJ. The 146 aircraft retain the standard Altimeter and ASI\Mach meter fit and standby horizon.
The PFDs and NDs require Signal Generators (SGs) and various failure warning lights/switches as well as additional selector panels for each pilot. They work well and are integrated with the normal GNS-XL/XLS/XLS Enhanced, as well as radar display, wind shear. wind arm information, and some TCAS information, and provided pilots with a nice plan view of the route etc.
There is, or was, a modification available that replaced the electromechanical HSI type display and the electromechanical FD with flat screens. These were called FPIs. The manufacturer sold these under the pretext that it would lower maintenance costs for aircraft operators. With this fit was a requirement for switch panels, warning lights etc, etc.
Hope that helps.