Flamenco skirts and dresses require a lot of material - allow 2 metres (2.5 yards) for a simple skirt and 3 or 4 metres for a dress. That much fabric is heavy! Bear that in mind when buying fabric to make a flamenco dress, and look for materials that are on the lighter side.
Don't go too far, though - very light material won't move well (or will fly up too easily!), unless you add a lot of ruffles to add weight at the hem. It may also be see-through - and voila, you have to add a lining, which adds to the weight, so you're back where you started.
Many professionally-made dresses have a cotton lining, for strength and sweat absorption - but make your own decision as to whether you need one. Modern polyester fabrics hold their shape much better and don't really need a lining to support them, especially if you reinforce your seams.
As for sweat absorption - if you wear a separate cotton-lycra cami under your dress, it will absorb sweat just as well, and is easier to wash - and you don't have to worry about it shrinking out of synch with the dress. If the dress has sleeves, you can also sew sweat guards under the arms.