As far as Mini PCs go, I'd consider Intel NUCs (currently NUC 12 Pro line), primarily because they have great firmware lifecycle support. A lot of cheaper brands in the NUC-like Mini PC space don't consistently release firmware updates (if at all), e.g. to fix security vulns, which is a deal breaker for me. Intel NUCs are validated for Ubuntu and RHEL. The main downside is that you'd be relying on an iGPU for gaming, so do some research on whether the Core i5-1240P's Xe iGPU would be able to handle the games you're interested in.