First - Image stabilization - You need this which most action cameras will have unless it is a relic my my hero 2.
2nd - ND filter - You need this if pointing through the prop. Eliminate the weird prop from your video. I've found that a ND32 filter works best for my RPM-2500-2550
3rd - Metadata (overlaying the airspeed and altitude) - Just neat.
4th - pick one brand and stick with it.
5th Editing software. - This is why you should stick to one brand.
I have 4 different cameras when I fly. I know, dumb, but I was trying them out to see what I like best and they are all very similar.
I use a VIRB 360, but haven't tried making a 360 video yet. I use the wide angle, mount it under my tail. I forget what mount I bought, but just make your own it will save you a bit of dumb money. The wide angle is just right IMO for seeing the wings and the gear raise and drop. The nice thing about the Garmin cameras is their software makes it pretty easy to overlay the metadata (airspeed/altitude). I email my flight data from garmin pilot app and load it into garmin's video editing software.
GoPro Hero 2 - I use this in the cockpit because I have the correct ND filter for it. ND filters remove almost all of the prop from the image and are a must if pointing out the windscreen. The bad thing is that gopros this old don't have image stabilization. It can be done with editing software but any modern camera will have stabilization.
Akaso v50x - GoPro knockoff without a good app. Records great video, but will only have image stabilization in 1080, not 4K (same with the Akaso Elite). I mount this under my wing. You can see in the video how smooth it is with the image stabilization under the wing. I mounted this with a bolt through a gopro sticky mount. The akaso elite is just like the v50x but more expensive. It is not in the video below, but I haven't noticed any difference with the v50x.
Editing software. - . This was a challenge since I had 3 different brands of cameras. It took days to find a good mix of software. I probably tried a dozen different freeware editors to find the right mix. I use openshot for the main video. It is easy to load 4 different cameras, sync them, then select the clips/views pretty seemlessly. If you go with all gopros or all garmins, using their respective editors makes this a lot easier, so I am told. Once I am done editing the video, including awesome music, I put it into Garmin's editor and add the metatdata overlays. I just really like the overlays. You may have to sync the timing of the overlays to your video too.
Below is the end product. Not great video, but I am learning. And if I didn't have a 3 year old I could have spent a lot more time editing.
Hope this helps.