I am debating the wall thickness for the tubes. I found a good website, http://www.stockcarsteel.com/dom-ste...-over-mandrel/ for steel etc at this size, they have lots of variety, and I ordered a sample of all the 3/8 inch tubes they had. I'm pretty sure I'll go with the .028" or .035" wall thickness (one of the 2 thinnest) any advice?