Which Barigain Fittings bulkhead kit for Island Breeze 60qt Igloo Cooler?

I'm making a mash tun out of a 60qt Island Breeze Igloo cooler (rectangular). Does anyone know for sure which of their bulkhead kits is the correct size for these coolers?



http://www.bargainfittings.com/index.php?route=product/product&path=47&product_id=85

I took a look at a similar cooler (island breeeze 28 qt) at walmart and it looked about an inch thick or less where I would install the drain. Typically, coolers with drains are a bit thinner at the drain so I *think* the 1 1/2" nipple would be enough. The worst case is, you get the wrong size nipple and have to drop a few bucks for a longer one at a big box store. Regardless of nipple length, note you may have to bore the drain hole a little for the fittings to fit.