I've got Rexing dashcams in all my vehicles. A few things I like about them:
1. Solid body mounted on windshield, with adjustable-angle lens. I've had ones mounted on a swivel, and they always get bumped out of alignment, or the plastic ball/socket would eventually fail.
2. Super capacitor, instead of internal battery. Capacitors are a whole lot more durable than any type of battery, which would fail after a while. Then it would end up corrupting the last video files when the ignition is switched off and the camera loses power.
3. There are several styles of direct wiring kits available for it, some allows for the camera to maintain power with ignition off, which allows it to record continuously or when a high G-force is detected.
Whichever
dashcam you choose, get one with rear camera (at least 1080P). A 3rd cam option might not be a bad idea for monitoring inside cabin, especially if the system is set up in surveillance mode.
If I didn't already have dashcams in my Stingers, I would seriously consider buying this:
Plug and play Dashcam The integrated stealth install makes it a great setup.