Don't know if I should buy the Umbrel Home or build my own... It's a tough decision.

Obviously, I can make something much more powerful. But the intriguing thing about the Umbrel Home is that it's so tiny.

However, I'm pretty sure it can only run Umbrel OS, which is kinda sad. 

 You're only limiting factor, that I can see from the specs, is the CPU.

You should be able to flash any operating system you desire. Even Start9.