You will need around 65db gain in your phono stage to use the XA.
XA may have a subjective refined presentation compare to the XI.
Both are a solid choice.
XA air core aligns with more exotic(expensive)low output cartridges.
"or there is still a way to get the ART9"
There isn't a compelling reason to look for a NOS ART9 -UNLESS you can get it for considerably less