I found
these comments at NWN Vault. From that topic, I got it there was a Solaufein mod for NWN, based on Weimer's WeiDU Sola. I followed the links to
Bioware forums and
the forum where the mod was hosted, registered and downloaded the mod. Then I used
NWN tool for opening it... and, yeah, Weimer's Sola content is all there - only, it's for NWN.
// me wonders if Kelsey NWN2 is next in line