A good rule of thimb for buying a lock is to spend a minimum of 10% of what you spent on your bike. Since I don't know which Coda you got, I can't say for sure. Assuming you got the just plain Coda, you should maybe spend $40 - $50. I wouldn't buy a U/cable combo, personally. I always lock my bike with 2 separate locks - one U (Kryptonite New York Fahgettaboudit) and one cable (Some Master Lock thingy), each with their own lock.
As far as parking goes - when the weather's crappy (cold, rainy, etc), I park in the ramp lot 1/2 block from work. When it's nice, I just lock up right outside the door to the building. Maybe a strategy like this would work for you, too?