Also sorry I forgot to ask.
Have you purchased your tube yet? If not I would recommend 3mm wall thickness alloy, over 1.6mm wall thickness gall tube or stainless tube. The alloy is cheaper, lighter, stiffer and is true 25mm metric tube. All the other types of tubes I have tried have all been 25.4mm (or inch). Many people have successfully used 25.4mm tube, so I will work, but I found everything just went smoother and fit better with the alloy 25mm stuff.
Which country do you hail from?