There are a lot of websites that are selling pro team cycling clothing that go down to a mens' size xs or euro 2 which fits a smaller (5'4" and under) frame. Some of my favorite sites that are reasonably priced are:
-www.velowear.com (has women's pro gear at very low prices)
-www.procyclegear.com
-www.bikejerseys.com
-www.bicyclinghub.com
-www.trialtir-usa.com
Most of these sites only have european sizes 2 - 7, but also offer size equivilants with measurements. If you're unsure, you can always measure yourself with a tape measurer. If you've never worn racer stlye clothing before, they do fit closer to the body so there's less wind resistance and less chafing. I started off with wearing regular cut clothes from performance or supergo, but eventually switched to proteam wear because I liked the form fit and much higher quality of product. I hope this helped.