I’m currently gone with the following sizes, and using 25.0mm 316 Stainless Steel conduit.
885.0mm X axis
720.0mm Y axis
340.0mm Z axis
These sizes allows me to have very little wastage from a 6mtr length of tube.
I’m also from NSW, Sydney, and I found an Electrical supplier just around the corner.
The problem is that the cost of this tube is way more then any other steel conduit.
But it is the correct size, as I went around to them and checked.