I have a 24v Northern Tools cordless impact wrench. Cheap, powerful and loosens everything once the brushes are worn in. Good deal and had worked flawlessly for the last 4 years. I'd recommend a 80 lb ft torque stick extension to tighten everything up safely before final torquing...although if you are using studs, avoid the all in one 17mm, and get an extension as the hex doesn't fit over studs. Ask me how I know!
