I may be a homer, but if you're going for consistency, go for LT. His upside for a monster game is just as high as LJ in any given week, but given SD's focus on the running game, and the fact that Rivers can make the plays if given the chance, opens things up for LT to be very consistent.
Right now I don't see the Damon Huard as any kind of threat to opposing defenses, so I'd say most teams are keying on LJ. He'll still do well, but I'd put my money on LT.
Edit: Looking back on your question, I misread that you had already picked LJ. Don't worry about him, he should have a great season, and I don't think you have anything to worry about. He's still a stud, just not as big a stud as LT.