Respectfully, I have to disagree. You didn't follow the thread all the way through. Microcenter sells no such parts that would work for this user. This OP's original question involved purchase of a mobo, , cpu and psu that would run his existing ram in a proprietary Dell Optiplex 5810 case and be compatible with Windows 11. He can't. The only parts he can use in that case with his ram are genuine Dell mobo and proprietary PSU which can only be found as used now due to its age. The cpu that can be used in the required mobo has been out of production for years so would also have to be found used.. and it still would not be Window 11 compatible.
This user now understand the obstacles preventing him from following through with his original idea, so I hope anyone else who might get to this thread researching a similar idea regarding a proprietary system can understand the why now as well.
It's all moot anyway, as this poster has wisely decided to purchase an OOB system that runs 11 on modern hardware, albeit I believe the system he has chosen also uses some proprietary hardware.