My first sff pc in a K39. i5-8400, RTX 2060 super, 16gb RAM, Alpenfohn Black Ridge, Aorus Z390i. All fan swapped with Noctua 90x14 for CPU and GPU and 40x20 for PSU.
Intel Core i5-8400 Rainbow Six Siege Benchmarks - Can Core i5-8400 Run Rainbow Six Siege? - CPUAgent
RTX 2060 benchmark with i5-8400 1080p, 1440p, Ultrawide, 4K benchmarks at Ultra Quality - GPUCheck United States / USA