While I'm late to the party I would like to add one thought, don't bother with a 3090 GPU.
If you can get any of the 3 series go for a 3080 at best.
I'm running a 3090 and it's excellent for my photography it really is overkill for MSFS.
Same goes for RAM, while I use 128GB and it makes my other graphics better there's not that much (if any) boost for simming.
:pilot:
Another thought: I must add that I'm operating at 4K on a 43" screen so the 3090 helps.