Of the two new models, the D435 would be the most similar to the ZR300. When the ZR300 camera module (the camera circuit board inside the ZR300 USB camera) was retired, Intel suggested in their 'end of life' documentation that manufacturers switch to using the D430 module (the camera circuit board used inside the D435 USB camera).
There are some important differences between the ZR300 and D435 though. The D435 uses the RealSense SDK 2.0 software, whereas the ZR300 can only use the original 'Legacy' version of the Librealsense SDK, or the RealSense SDK For Linux. Also, the "IMU" components in the ZR300 (gyroscope, fisheye, accelerometer) are not in the D415 and D435.
This feature can be added to the caseless module versions of 400 Series cameras by attaching a separate optional T150 Tracking Module component to the D4 Vision Processor component of the camera via a 50-pin connector. Page 41 onward of the 400 Series' data sheet document describes the Tracking Module.
The 400 Series cameras can work with any Intel or ARM processor. For the D415 and D435 USB cameras, a USB 3.0 connection is the main requirement.
The RealSense SDK 2.0 has full support for using ROS with the 400 Series cameras.