sliding door rail

Thanks for reaching out to us! We unfortunately don't sell complete thresholds, but we do sell a patio glass door track that might work for this application. See our 80-106. I'll also share a video below that details how it works and how you may be able to use it in this application.

As for the rollers, I see you've made a few other threads with us here. I'll answer these one at a time for the sake of clarity.