I think MSI mobo will be better.

RAM at least 16GB. Look for higher Mhz if price not much difference. Min 3200Mhz. You want to buy a set of 2 stick or 2 of same spec to avoid any incompatibility when running dual channel. If purchase another set later time, it might get revised and not same spec.

256GB might not be enough once you start install bunch of programs. Get PCIe 4.0 SSD, so that later when you get another SSD you just add to another slot. No need to replace the existing SSD.

RAM always change, sometimes even when at same time due to different component supplier. Advisable to get those pack of two.

With 256GB you likely be out of space after install some programs. Games also take almost 100GB each for AAA title

Depends on packaging, some do have date or code to see. Will be better if seller can confirm both from same batch.