New and used Specialized Command Post IIRC Internal routing, 30.9mm x 125mm, $129 for new, $75 for the used one. Also have 100mm drop. These are the most durable droppers in my opinion.
This is the only dropper that also provides a roughly 1" setback, great for frames that are a bit too short, or just wanting a slacker seat tube angle. It works VERY well for this.
I-10 and Chandler Blvd
See my "other items" link for more parts and TIRES