Congrats KG!! Try the aerobars you have but for where you live I wouldn't worry too much about having them. Everything is up or down so if you like the be in the drops, you may not need the aerobars at all and it is certainly much easier to climb on a standard handle bar set up.

I agree about the gearing change bu maybe you could even go to a 11-27? I would definitely go with the 27 at least.