OCTADE
@octade@soc.octade.net
I don't know about an IPv6 donkey client. It seems that interest has waned enough that most projects have stagnated.
I think if you connect aMule via a TOR proxy it should be able to reach the network. Perhaps it may work with torsocks or proxychains or socat.
DarkMX works great over TOR and it should connect regardless of your IP scheme.
RetroShare (http://retroshare.cc) also has built-in TOR connectivity and it is open source with a Linux repo. It is F2F instead of P2P. You have to invite people to join your network. This can be a big upside for security but would usually mean less files to find. RetroShare also has built-in messaging and forums.