I've heard the Chorus speakers (705 or 706, I don't recall) and yes you will probably want to move up to the 8004; even that might not be enough. I've played some pretty hefty speakers on my PM7200, which is also HDAM but puts out an actual tested output of 105w (rated at 90). Despite that it isn't really geared toward being driven hard constantly; even with the massive heat sinks it can get pretty hot when driving difficult loads.