If you've ever wanted to own a true Texas barbecue joint, there'a a really good one -- Fatboys BBQ -- for sale 80 miles northeast of Dallas in Cooper. We first met and wrote about Heather Hoff & Shannon Bankston in 2012 when they ran Fatboys in the tiny town of Ladonia, population 612. Within a year they had moved the business to nearby Cooper, a bigger town with state Hwy. 24 running through it. When we saw earlier this summer that the joint was for sale, Marshall Cooper and I headed east to visit. Fatboys BBQ is a classic…