I have their Adjusta-Fit Closed Front Fleece liner, which I use as both a liner and a cooler. I also have their Poly-Tech multi-purpose Cover. That one is a bit heavy, but I've used it as both a cooler and a light blanket.
You were asking for coolers, but FYI, my favorite from them is the nylon blanket liner. For SoCal, it is perfect at 180 grams of fill, and they are not expensive, so I can buy several, just have a turnout sheet for on top, and have a clean liner for next to the horse.