Ended up going with an option on Amazon that cheap and simple to install. Works very well. Too well, in fact; at higher pressures it’s actually too much. It’s also coldwater only since a hotwater option would involve drilling through walls/cabinetry for either electrical or a hot water line. The cold water is still a bit shocking when it kisses my bunghole but it’s not as bad as I had thought it would be.
It was the easiest and cheapest option and achieves what I wanted. The heated seat would have been nice but isn’t justified by the additional cost in the product and cost in modifying my bathroom for it.
I was actually eager to put it to use but muh bowels are real quiet right now, despite having fast food for lunch. It’ll have to wait, I guess.