Some kind of bar setup for chins, as Bear03 suggested. If you can't do that many chins at first don't worry about it. The more you do the stronger you get at it. Can also do BB or DB bent over rows. Do the BB version with a curl grip and pull to the lower abs. Do the DB version with a wider arc for more involvement of the rear delts. BB cleans or Hi-pull are excellent for total back muscle mass and power, from the top of the traps to the muscles around the lower back. Pullovers (BB/DB-bent or straight arm)) are a prime lat builder, giving thickness and width. Also affects the pecs,triceps and abs strongly. Good Luck.