3-strand rope is an economical choice for your windlass rode. Keep in mind, the windlass does not stow the rode in the anchor locker - gravity does. So make sure you have ample depth and volume in your anchor locker to accommodate the length of rode you have chosen.
8-Plaited nylon rope eliminates some of the service problems associated with the 3-strand ropes. 8-Plait uses 8-individual braided strands woven together that allow the rope to be relaxed. But, when under load, it tightens up to a firm lay. The higher the load the harder the lay becomes.