Hi Kate, I also have small feet and not long legs. I looked for over a year for tall boots. Finally, I put on a pair of Sergio Grasso field boots, and they fit like they were custom! I have had them for more than 3 years, and someone the other day commented about them needing to be broken in. When I told them they were almost 4 yrs old, she was floored. They truly look that good.
At 50 years old, I usually wear a size 3 in kids shoes. In paddock boots, I can get away with a 4-5 if they tie. Inside the boot it is stamped: 86 3500 37 0
The zipper is in the back, and I have never had an issue with it.