As others above have said, the 5700x3d should be fine for the sim in1440p. The key reason is the x3d cache so I wouldn’t recommend a non-x3d cache processor.
I think the 7800XT would be the best choice for the sim with 16gig of vram. If you wanted to save some money I would definitely look at the RX 7700XT GPU instead of the 6750XT (maybe get a good Black Friday sale price…). The 7700XT is almost on the level of a 4070 with 12gig vram and it is better than the 6750xt and will run cooler and less noisy. I have one on a secondary PC that I bought open box and was very impressed. It can run 1440p no problem and can even run 4k on medium/high settings but the 12gig vram holds it back and you’ll get some stuttering when the vram fills up. It’s price point is between the 6750xt and the 7800xt.
If you wanted to save a little money in order to purchase a better gpu (7800xt) I would definitely consider going with 32gig of fast memory. Unless you really need 64gig for something specific, the sim will run great with 32gig.