I’ve been doing a lot of research on this over the last 2 weeks. I have my machine in the mail, but have not tried anything myself on my own hardware.
For Stable Diffusion, 8GBV is usually considered absolute minimum to do very basic stuff only. 16GBV or more is the basic need for a decent workflow.
For AMD I have seen multiple sources saying to avoid it, but there are a few people that have working examples in the wild. Apparently, AMD only supports the 7k series of GPUs officially with ROCm/hips/AI stuff.
Officially with Stable Diffusion, only nvidia is supported.