The PegTop track and range bars are quite nice and easy to use: https://www.pegtop.net/delphi/components/common/screenshots.htm
...and there's couple in the SO post: https://stackoverflow.com/questions/4387690/component-similar-to-trackbar-to-enter-a-range-of-values
...and if you can wait a week or so I will be releasing one of my own (based on Graphics32 though). I have the track bar part completed so I'm starting on the range bar part now.
DevExpress also has a range bar and I believe TMS has one too.
Personally, if I weren't writing my own 🙂, I would go for the PegTop range bar; I have used it with success in many projects.