A lot of this really depends on what CPU you want to run. Open HW Monitor works great and has a GitHub for basically any Linux distro it should just work immediately for CPU, Mobo, GPU, fans, and smart.
For the actual Mobo, I'd probably lean towards some that actually aren't overly fancy as often some of the more crazy ones have a lot of extra hardware that may or may not work correctly in Linux. None of the big companies seem overly interested in specifically targeting Linux users, but all the major stuff like Intel SATA/USB, realtek audio, and most common NIC chips should be no problem anyway, and much like installing Windows, you're often better off just ignoring anything packed onto the disc and running to grab the latest elsewhere online for drivers should it be relevant.
I will say that it's handy to have a basic old $5 60gb-80gb used SSD on hand to keep a Windows install on, you can boot to it to do bios updates from the major MFG utils there if you don't feel like jacking with making bootable freedos USB sticks. Way on back, I always preferred the dos way of doing it, but tbqh, now for any major brand, the windows bios update utils work totally fine, while the Linux ones at least for me haven't been so hot, or very available by contrast.