your in San diego, Derailleurs all the way. I don't have experience with IGH but I have experience with commuting. Also, if your not dead set on steel, consider the Nashbar touring frame. for under $100 it's awfully hard to go wrong with it. I'm 90% done with my commuter, just need to get my rear wheel finished, i'm using a backup wheel while it gets built.

I also like being able to swap out wheels as needed. The nashbar frame has 132.5 dropouts. I've got 700x37 tires on it for comfort since i'm 245lbs but i like haveing the option of throwing another wheel set on with narrower road tires should I plan to take it on a long group ride or having a set of wheels with knobby 29'er tires on it for really bad weather or if I'm taking a trip somewhere that is going to have dirt trails. the regular route I commute is TERRIBLY potholed but group rides that I would do are on relatively nicely paved roads so its nice to make a simple swap of a wheelset rather.