I'm downsizing my Madone's 9spd triple to a 9spd compact double this weekend, but have some elementary questions.

How important is the crank in the overall scheme of components? In other words, do I need to stress over the quailty of the crank?

The bike shop has options for me from Ritchey and FSA Gossamer because "Shimano doesn't offer a compact double." I'm not familiar with the models in question for Ritchey or FSA Gossamer, but will hit the web this afternoon for some generic research. Is one brand unacceptable or preferred over the other? What model(s) would be comprable to Ultregra?

Despite my LBS, I recall seeing a DA compact. What about Ultegra? Does Shimano offer a 9spd compact?!

If a crank is important and Shimano offers one in DA, is it worth the upgrade $?

Thanks and pray for the weather to break!