Well it is definitely hard to shop from this side of the globe, but hey if you have an extra plane ticket laying around.....
I am more than willing to ship some, the conduit is very cheap but I have no Idea what the shipping would cost. If you can wait until this weekend I can go get some and see if I can fit it all in one box. Max length would probably be just under 24", Maybe longer. This is something I wanted to start offering so I have been looking into it a little, all I know is it is not flat rate like my other shipments, but the shipping didn't seem to crazy domestically.
If you can't get conduit in either 23.5mm of 25mm would be to see if your hardware store has closet hanger rod we have it in a bunch of sizes here. Try to get anything but the painted ones, that stuff seems great it just cost more than the conduit.
If you can't find that, you should be able to get aluminum extrusion, you can get either round or hexagon. usually you can even get this cut to size, for a little extra.