I'm looking for some flat brown boots that I could wear with knee length skirts in a business casual type office. No knee highs because I have short legs so they're always too high on me. I'm probably looking for a Chelsea type boot, but I don't want it too wide at the ankle as I have very narrow ankles, so they can look wrong with skirts and I want a slightly chunkier sole but not too chunky that would make them overly casual for work. Any suggestions for under £100?