There are some screwy answers here based on the information you gave. I really don't think your looking to pawn off REI gift cards and search for months on craigslist for the right used bike, which will then immediately need a tune-up.

Clearly you have a $900 gift in your hands and want a good bike at REI where it is very convenient to purchase, and lets not forget their great satisfaction return policy.
You want a good road bike for the money that must come from REI with what you have. OK, so let's help you here.

First, no matter what people will tell you here there are better deals elsewhere. However you have basically $900 off a bike so that is the best deal.

Second, if the sales guy you had wasn't good, go back and get someone else working at the time. You may get a good person and answer all your questions. If you have an avid road cyclist friend that can give sound advice then bring them along.

The Cannondale Synapse 7 is a good choice but people here will have a hard time recommending spending $900 on Shimano Sora components. They work fine, but the big issue is the shifters use a cheaper mechanism and clunkier operation method. All the components above Sora use the same system but just get lighter and a bit smoother as you move up the component hierarchy.

I have to say, my advice would be the 2012 Cannondale Synapse 6 with brand new Shimano Tiagra 10 speed for $1099. Since it is a 2012 you can test ride what they have for sizes and they can order this bike for you. You end up only paying $200 plus tax out of pocket. Shimano Tiagra just went to 10-speed like all the other higher component groups and will work very well for you. It also has a compact double crank instead of the triple on the Synapse 7 and Novara Strada. The Synapse is a very well liked model, the Cannondale brand means the bike has more resale value, and quite frankly on paper it has more engineering and testing put into the frame. But I haven't ridden all the REI choices to say if that means anything for real.

For the REI choices and your needs, the Synapse 6 is a good value. The 2011 Strada is also a good value but is sold out so all they have left is it and they may not have your size.
If you end up really like road riding, the Tiagra components will keep up for a long time. With the Tiagra you will think higher components are really not that much better and you are happy with what you have (unless you come into extra money to spend in the future). With Sora you will realize higher components are much smoother and nicer to use and regret not having spent that $200 to get the Synapse 6 (or Strada) in the first place, because upgrading will cost so much more.
Also see when the 2012 Strada will be released because at the same price as the Synapse 6 but with Shimano 105, this may be a very good option for you.

Don't forget the expenses for other stuff too like helmet, pedals, shoes, clothes, etc. You could probably ask for some of this for Xmas.