Preferably, the OP would want just one SIM card. Buying one on the first stop at LAX is really not feasible, I can't think of anywhere that sells prepaid SIM cards inexpensively. As to the one SIM card, a Rogers card is expensive, and fairly difficult to come by. An AT&T GoPhone card won't work in Canada. Therefore, T-Mobile is the way to go. Buy it off of e-bay, pop it in when you get to the States, and it will work fine in CA, AK and BC.