I use G.Skill Trident Z Neo Series 32GB (2x16GB) DDR4 3600MHz CL16, love it.
DDR5 6000 cl30.
@phoenix Yes, CL lower better.
6000MHz CL30 or CL28.
Try to get the lower the CL you can, i have a similar build with CL30 6000 32gb that is amazing
Crucial DDR4 RAM is recommended.
For 7800X3D, your best choice is to get the DDR5 6000 CL30.
@valler And eBay.
What is the price?
Release date in late January.
It will be hard to get RTX 5090 at launch.