For me an SBC is really a PCB with components on it à la RPI, I haven’t see a lot of x86 like that except industrial one and they are $$$.
Have you thought of a beelink mini PC? This one is $149… https://www.amazon.com/Beelink-Lake-N150-Upgraded-Computer-Business/dp/B0F3C6R47G





In general, yes… I used Ubuntu years ago but for almost 10 years now it’s MX Linux (Debian based), only problem I had was on my brand new PC the wifi card was new and not well supported by the kernel, but with new kernel/driver it improved and now I have 0 problem.