I started out using a large past pot to mash in and put that in a warm oven (heated up, then turned off) for the mash. It worked fine, but after a while I picked up a 5 gallon beverage cooler and put a ball valve on it and I REALLY enjoy using it. It's so much easier than messing with the pot. I don't even use a manafold. I just get a big paint strainer bag, line the inside of the cooler with it and add my grain and water.
I think the end result will be the same. The grains will mash the same, but the cooler really makes it a piece of cake.
"Science + beer = good!"