The setup I am using is a Rubbermaid Polycarbonate 12 quart container and cover as a vessel. I cut out a close fitting opening in the cover that fits both my APC and AnovaOne. I also used a sheet of mylar bubble insulation to wrap the vessel and cover. I shaped the insulation like you would wrap a gift package with a separate bottom and top cover. I cut slits in the cover insulation to clear the circulator. I use a strap of nylon webbing to secure the insulation around the container and the cover insulation to the bottom. The container and cover cost $21 from Amazon and the bubble insulation was $2.20 per foot in a 48 inch width from OSH. I bought 3 feet.
I use a Cambro cooler similar to yours for large items. The polycarbonate is a good insulator on its own; your insulation improves it considerably I would imagine. I find myself using a stock pot for most of my cooks and I might look for some insulating material that I can fashion to fit. Rubbermaid and Cambro also make smaller containers that look like they might work pretty well for smaller items.