Do you know why you have this pain? I have shoulder/neck & arm numbness from cervical disk problems. Riding position really helps - keeping your elbows in so that your shoulders don't raise around your ears.

I'd stick with carbon fiber because of the road vibration dampening effect. I just bought a Madone, having come from a custom steel bike & the difference is astonishing. The H3 series, women specific, is nice because the ride is a little more upright.