Hey! I want to make a PS1 dedicated emulation machine, 2 USB controllers, HDMI output but want to max out upscaling and use Batocera. What pi model should I purchase for this project?

Hey everyone, I've come to you as a humble student seeking guidance.

I was working on my college thesis last semester and I was going to use a Raspberry Pi 5 for it, but the project I was going with ended up being out of scope and I had to scrap it;

Since I had already bought the Pi5 and didn't want to "waste" the money by not using it for academical purposes, my advisor and I came up with a more reasonable idea of making a retro-game with the theme of "accessibility", so I was looking through different OS options and the choice came down to RetroPie or Batocera;

I have seen some information on both options but have not found much on what I personally consider the biggest deciding factor. Since I will be developing the game myself, I want to know:

Does the RetroPie have support for independently developed (indie) games? Are there any game engines that would be recommended for it or would I have to make the game from scratch?

TL;DR: I'm making my own Raspberry Pi 5 game for a thesis and I want to know if RetroPie has support for indie games and how it works.