Get a recon, got to a local trade type place, around £55 for full recon, sometimes the bearings can be right shits to get out without cracking the end casings, the pulley itself simply bolts on whichever one you need, the alt will be the same, xr4i alt can be used, as can 1.8D escort mk4.
You could just ask for a part repair, should be about £20 or so just the bearing, but how far worn is the rest ?
tabetha