In the end you have three opportunities:
Envoy, which I were able to get through eBay and which works wonderfully smooth...:-)
Samba, which can be a pain to setup (but it's free...)
or, third, some ftp daemon on both machines. I would suggest to setup ftpd's and use the nice and easy to use "FTPMount" to access each Amiga through Workbench or your favourite file manager.
I personally use Envoy for my Amigas and FTPMount to access my Solaris/dtk workstation.
