Even with a mini itx board it's wise to have 2 m2 slots. One for a low capacity high speed read and write cycle for the swap file to go and the other just a fast read high capacity ssd for system and performance apps.
I think it's also wise to choose the latest ram but with the slower Hertz because this is more energy efficient and at the highest capacity.
Then you put an RTX 3050 in and what the swap ssd and high capacity ram allows for is a better upgrade path as software requires more ram you get better buffering as it will use this feature more with the specific swap ssd and all that will need upgrading 5 years later will be a cheap more modern GPU. If you ignore the second m2 and choose less faster ram then you will have to upgrade to a new computer sooner. It's also worth making sure the PSU is a good stable high quality unit. Why spend extra on a 3060 when you could get a 3050 and more future proof your system and save some electricity and future expense. The best time to build such a system is a little after they shift pcie generation then you get a good budget gaming experience. This gives you roughly 6-years gaming out of each main build. when you Upgrade the GPU midway you could choose a slightly higher ram edition and use the old GPU on the new build to save money stretching the longevity.