This convenient listing of the types of thread is at hammockforums.net but I’m preserving it here as well in case it goes away, and because I need this information myself for sewing projects, and always forget what the various mara and tera and tex sizes actually are, and how they interact and relate to things like needle sizes.
Note that the spools sold by ripstopbytheroll and diygearsupply work fine on regular sewing machines spindles though they tend to rattle around a bit, you can get around that issue by simply making a larger spindle to go over the regular thin metal spindle on the sewing machine if you find it annoying or hard to work with.
Units of Textile Measurement Gütermann Numbering System