Converter uploads a sysinfo binary that collects the source information which is built for Linux. While expected to run on unsupported Linux distros, too, Solaris is not Linux.
About the other way - only booting from helper ISO. Converter server passes the necessary conversion parameters to the helper as part of the conversion process. If you only boot from it w/o this being initiated as a conversion, this is just booting from a live CD.
Probably installing Solaris on a new VM from scratch and them copying the files will be the easiest way.
Regards
