He specifically mentioned "best gaming PSU and CPU Cabinet for my CPU". Based on my assessment, when he says "CPU" he actually means PC (note the "CPU" Cabinet = PC Cabinet). He selected a high-end Gigabyte Z270X Gaming 5, which is designed with a LOT of RGB lighting and meant to be showcased, thus, the glass case to complement it. The CPU in question was the "i5-7600" he listed, as I am still awaiting the OP's reply to my query above (if maybe he had a typo error and accidentally dropped the K). Hence, my recommendation to get the i5-7600K instead of the locked i5-7600. The RM550x has the best warranty/quality for a PSU, with ample upgrade headroom, as a direct answer to his query "what is the best gaming PSU". OP did not provide any budget, only a qualifier word "best", specific to the PSU and "CPU (i.e., PC) Cabinet".