Well there is definitely a couple things to consider before you purchase a cooker. You may think that you may not need that big or powerful of a cooker since you are still doing extract batches but don't make the same mistake I did. I bought a 13" bayou classic cooker which produced 55,000 btu. Now my problem came when moving to all grain and my bigger kettle was too large for the 13" rim. My kettle is 16 3/4" in diameter and when I try cooking with it I can't turn it up all the way or else it becomes dangerous because it shoots flames out the bottom close to the valve. Well that was my experience.
Whiskey Barrel: Russian Imperial Stout
Bottled:Amber Ale, Bitter Chocolate Oatmeal Stout
Drank/Gone: Red Ale