Need help with additional power problems.

I start this off by saying I don't know what I'm doing, I just got a vision and am looking for advice.

I have had a 2015 gen 3 prius recently that I had after market audio alterations to. I had a Kenwood DMX9707S, Focal Flux Evo components 6.5 in the front, changed from the 6X9 size. 6.5 in the rear door, no components. Powered by an alpine 1200 watt 4 channel amp.
2 12 in alpine Type R 4 ohm subs, powered by an 800 watt Rockford Fosgate monoblock.

I unfortunately got into a wreck that totaled that prius and now I'm looking at the JBL versions of the prius because I can add the components to the rear doors. I wanted to add a set of 6x9's back in the set up for more mid range along with my highs and bass. I also wanted other customizations like Airbags, interior leg LEDs, a louder horn and starlight headliner.

I understand this all needs power, which is why I am here. Since it doesn't have an alternator, I don't know other ways to power all of that.
I've looked into adding a 2nd Aux battery , but Im not sure if the 2nd battery would be properly recharged and or be enough to power all of that.
I've also seen PHEV Conversion Kits and wondered if that could be a solution, or a part in a solution with the formerly mentioned modifications, same with the hood solar panels systems I've seen at lensun.

Now I know I'm going to get asked why, personal preference. I love the prius platform, I like the look, I just wanna add alot of stuff I like to make it look the/sound the way I want to. PLUS, I've never seen anyone do it, so I wanna try. I just need to know if it's completely impossible to come up with a powering solution, or if im on the right track.

Thank you.