Green Mountain Consulting, riding the rising e-commerce tide, closes Monday on the purchase of a new headquarters in East Memphis. The logistics firm, currently at 7240 Goodlett Farms Pkwy. in Cordova, is buying a 60,241-square-foot office building at 5860 Ridgeway Center Pkwy., near Poplar Avenue and Interstate 240, confirmed Newmark Grubb Memphis' Greg deWitt. Green Mountain will take about 26,000 square feet in the building, bringing it near capacity, said DeWitt, vice president of brokerage.…