I have also read the internal wiring on the Canterbury SE is Acrolink. I am using Auditorium 23 speaker cables with my Canterbury SE & like the combination very much with my 300B amps. Auditorium 23 is designed for high efficiency speakers, you can find many good reviews. Can't really comment on the bi-wire question of OP as I have not tried this yet. However I would strongly suggest trying the grounding cable option offered, if not done yet, as this yields noticeable reduction in hash picked up; makes the sound smoother & cleaner.
Tannoy Speakers & Bi-wiring
I have a pair of Tannoy Canterbury speakers using Atma-Sphere amps. Currently I am using single wire (audience AU24) and the supplied brass jumper. Wondering what the experience of any Tannoy users out there is in bi-wiring and what kind of wires you have used. I'm thinking about trying this with a budget of about $1,000 used so really can't get into the mega expensive cables. Really curious.