Have to say I'm shocked by the number of posters on here who think the problem comes from no ils or papi. One, you do not have to accept a visual on atc's terms. If you are too high, extend the downwind. Two, visual or not if you feel like you just don't have the skills required to fly such a fearsome maneuver, put another approach in such as the rnav and use that for guidance. I'm fairly sure nobody operates into sfo that doesn't have rnav capability. If they do operate without it, I'm sure they have the competence to fly the dreaded visual.