@hetsen: Like I said, umodel works fine with both kind of meshes and textures if you'll open decrypted upks in it, so you can export them as usual. You just need to decrypt all upks with the tool you've linked and rename them afterward. For example, following batch will do the work, just place it with nosgoth_decrypt in the folder with upks:
for %%a in (*.upk) do (nosgoth_decrypt "%%~fa")
del *.upk
rename *.upk.unpacked *.
Though it will delete all original upks and you'll need a lot of free space, since decryption tool also decompress files as well. Alternatively, you can run only the first string from the batch, move "unpacked" files somewhere and then run third string from the batch on them.