If you decide to get a cooler, go for the 10 gallon if you like to brew big beers. I have a 5 gallon and a 3 gallon mash tun. I wish I had a 10 gallon since I have a recipe to brew which has 14 pounds of grain. I think I will need the 10 gallon.
Primary 1: Oatmeal Coffee Stout
Secondary: American Mild IPA
Keg 1: English Bitter
Next up: Double IPA for friend, Kolsch, Graff, American Wheat, Dunkleweizen.