As someone trying to spec out a Ryzen workstation right now I can tell you it's actually harder because Ryzen (unlike EPIC) uses UDIMM ECC, not RDIMM ECC. It's a niche that very few companies wanted to service before AI ram madness. Now the only vendor I can find is v-color:

https://v-color.net/products/ddr5-ecc-oc-u-dimm-server-memor...

But they no longer have 6000mhz stuff in stock (which is ideal for Ryzen due to the 1 to 1 speed match to the memory controller).

It's frustrating :(