I didn't quite determine if you have a solution or are looking for a solution, but a Raspberry Pi 4, 4GB with a passive fanless heatsink case can run Pi-Hole and Home Assistant without breaking a sweat. I use a FLIRC case.
I also want to do some routing on a gigabit link, so the RPI doesn't scratch that itch. I'm also not comfortable with the various horror stories I've heard about SD cards dying in Pis (although I've run one with home assistant for several years with no issues).
I'd also like to avoid running external drives, the goal being to have a self-contained unit. I'd rather have a larger unit instead of multiple small ones that require cabling (mostly for esthetic reasons) and various dongles.