I've got a very lightly used Canadian Fishing Reels 2:1 Mooching Reel and a custom built rod by Mike Rumig. We don't use it very often, so I would part with it. $900 picked up. Reel is blue and silver.
These slide into a track. I have Cannon 18" tracks mounted to them, but you can remove those and attach your downrigger.
$200 picked up, or buyer pays shipping