Jim, go to the two Colorado dealers and check out all the trailers you can. See how the bed feels, see if you fit on the toilet (a lot of people's legs hit the door), sit in it and tell the salesman to go away for a while. Take a lot of time. Do not bring any money or credit cards with you so you cannot put a down payment on a trailer before you are ready. LIkely that the 2009 and 2008 are the same, and there still seem to be some new 2007 Airstreams at some dealers across the country.
When you do make a decision, start looking on the internet for dealers because you may well find a dealer in another state who will give you a better deal and service on a 2007, or a new 2008 may be cheaper than a used one.