Huh; that's weird that it's not specified. You might contact your local dealer and see if they can't hunt that information down for you. In any event, I wouldn't go with anything but a compact 50-34 and a fairly wide cassette if you're worried about climbing. That said, cassettes can be swapped out and, depending on how wide you want to go, you may not have to change out anything else other than the chain. Talk to your shop about how much wider you can go without having to worry about changing out your derailleur. I, personally, would prefer the 50-34 crank coupled with the 11-28 cassette.

What gearing did you have on your old bike?