http://www.playwithcarbon.com/carbon-roll-wrapped-tube-1m/www.carbon-tube.com/round.phptwo that i found from another thread on Seabreeze... looking for some myself though these all seem to be not quite right for my snapped naish paddle (which has 25mm outside diameter and a wall thickness of only 0.75mm or so.
at about $53 per m (and I need two) its almost not worth doing... for a paddle that will be a bit heavy (if i go for thicker tube).