Well, I can tell you what NOT to name your daughter! I know so many Sarah Michelles that it stopped being funny about the 8th time. Michelle is a very common middle name for other names, too, such as Jennifer. I suggest that if you MUST name your daughter Sarah, for heaven's sake give her an unusual middle name she can fall back on! I would go by my middle name if I liked it, but I can't stand it. That's why I come up with nicknames like "Skylark" to help me stand out from the crowd of girls with my same first name.
If you want to go unusual with her middle name, you could name her Sarah Zephyr, Sarah Eulalia, Sarah Athalia, Sarah Diantha, Sarah Casadana, Sarah Lilyasa, etc. (As you can tell, I like unusual names and have even made up a few.)