Ana, I have to echo the posts about getting a proper fit, especially with a fitter who has access to a Fitcycle.
Like I said earlier, I'm also 5-1 and needed sub-170 cranks. I always thought I needed 165s but when I was thoroughly measured, it turns out I needed a 167.5 because of the length of my femurs. Since I was making a substantial investment at the time (Red cranks + ceramic BBs) I wanted to make sure -- and I'm glad I did!
Also, I suggest you hook up with some local cycling clubs. Their members can be a treasure trove of good information (finding the most reputable shops/mechanic, how to get parts in your neck of the woods, borrowing/trading components, etc). Most have a forum or email list that is handy to get information out. My club is a tremendous support group for me and have always responded if I wanted to try out a new wheelset, saddle or stem. No need to go it alone when working on a bike fit! ;)

