Sure, buy the battery powered Mobius with a separate super-capacitor, as long as you actually have a use for a battery powered Mobius, otherwise the battery is just a waste.
While the Mobius 1S offers higher resolution and better low light performance, you are seeking to match the performance of the A129 which is also an older, already somewhat obsolete camera. If you really want good dynamic range then invest in a camera with the new Starvis 2 sensor like the A119 Mini 2 which offers a dramatic leap forward in dash camera performance, especially in the area of dynamic range.
When people wish to capture the interior of their cabins they often purchase a three channel model which comes with a camera module designed for this purpose, but I'm sure you could use a two channel camera and mount the rear camera facing forward. It is a question of whether it will capture what you need, but you have not explained why you want to do this in the first place, so I have no idea if this would be suitable.