hi Steve,
not a new lead, but thought i'd share my experience with Kaus's CF tube.
I just retrofitted a Carbon Fibre Foam Core tube for my 10inch Mirrors and has been the best investment I've made.
I got the tube from Klaus in Germany as mentioned.
The tube is 7.5mm thick as its a foam core which is what is recommended for AP.
Its extremely rigid and strong enough to hold the entire weight without tube rings. so I got Celestron Dovetail and screwed it on and it holds the weight with no issues.
can't recommend it enough.
one more major advantage i've found is that the foam core acts as an insulation meaning I've never had to turn on my secondary dew heater in a recently wet night at heathcote and other dripping wet nights.
Another member had a skywatcher CF tube next to me and it was dripping wet inside.
btw, i have no affiliation with Klaus. just a very happy customer.
http://klaushelmi.de/en/
the 1m tube cost me around 260 euro landed, but you'll have to check prices with him.
Cheers
Alistair