Yeah unfortunately i'm also still on river-classic, so can't be of much help regarding the new river framework and its window managers. My distro hasn't packaged any of the new river stuff yet, and i couldn't be bothered to do it myself. It's hard to say how much trouble you would have setting up a compositor, cause they all have different configuration languages. Some like Sway use their own syntax, then there's river-classic that uses shell script, or even qtile that is configured in python. I use waybar as a bar for most of my compositors (except qtile, which has its own bar and is also very good). I use Fuzzel as my launcher. I have a few themes configured for my programs that i switch with a script, which mainly consists of some sed commands that replace lines in my configs, and then reloading the programs if necessary.