Most designs dont use separate thrust bearings. They use back to back angular contact bearings which handle both axial and radial loads. Many people just use regular deep groove radial bearings which are not designed for high axial loads, but seem to work fine in low usage home applications. Many people have the ends of the screw turned down smooth to accept the bearings, but many just get bearings with an inside diameter the same as the thread diameter and use the rod as is.