I am looking for suggestions for accessories on which to mount/attach several cameras.

I would like to arrange multiple NVR cameras on a portable rig. These are the security cameras of a Network Video Recorder. There is a central unit (the NVR?) with a mouse and connected to a monitor that will sit on a desk in one room. There are 8 cameras of the type that is meant to be mounted on a wall with screws. Each camera has a power cord, but they transmit their video feed to the central unit via wifi.

I want to arrange 4 cameras on a small cart or support unit, like a laptop cart or one of those vertical poles on 5 wheels that are designed to be pushed around in a hospital, for example. This cart will be pushed by a technician from one room to the next and the 4 cameras will be pointed at a person (a research study participant) so that an interview can be recorded. The reason for multiple cameras is to minimize the problems from occlusion by the interviewer and from the client turning their face left or right.

The other 4 cameras will be in the hallway to capture the research participant walking through the hallway. They will be mounted on a handrail that runs along the entire hallway.

I am considering using supports that are meant for lighting equipment, but I have zero experience using this equipment. I envision one support for each camera, with two segments connected by a ball joint that can be tightened, and at one end a clamp chat can hold a security camera (a little smaller than an old-fashioned consumer-grade camcorder), and at the other end a screw clamp that can be attached to a cart's surface or to a central vertical pole.

Among various systems of rigs/lighting supports/etc, is there a system that might be well suited to this purpose? I do not need a high-quality system like stabilized jibs, because the cameras are very light and the rig won't be moving during video recording. The technical quality of the video will be on the low end, and there is zero artistic value. I am hoping to achieve this by spending a few hundred dollars in total (which means I might resort to coopting the arms of several adjustable desk lamps).