Oher will probably be there, and wouldn't be a terrible pick, given that we only really need a RT, but the Niners could wait until the second round for a tackle, as this draft is pretty deep at that position. Orakpo and Maualuga will go around then and could help the team. I think they could trade down a little and still get Brown, Raji or Michael Johnson as well.
Bill Walsh once suggested that it was a good idea to take a QB in a late round of every draft. These days, nearly every QB is a gamble. If you gamble in the first round and fail, your draft is in big trouble. If you gamble and fail on day two, even if you do so more than once, your draft can still be salvaged.