What in lords holy name are you talking about? A real life one? Ok ok here is what you need, you need a power armor T-51 which doesnt exist, and a man (good luck) to fill the suit, along with either a minigun (AND ANOTHER GUD LUK) a gatling lazer or some laser weapon (bear in mind, only the minigun exists and its more or less impossible to hold if you aint Hulk)
http://postapocalypticearth.blogspot.com/2011/03/us-navy-successfully-uses-laser-to.html
http://postapocalypticearth.blogspot.com/2012/01/railgun-in-production-by-2018.html
http://postapocalypticearth.blogspot.com/2012/02/navy-to-test-32-megajoule-em-railgun.html
And bear in mind there are already lasers that can cut through metal and are used in industrial systems. And just look on youtube for people that have actually made gauss and laser "weapons". The only thing holding most of these technologies is power, they consume massive amounts of it energy. There are other things holding them back but not having enough energy to get the desired results is the main problem at the moment. Also bear in mind we are already using exoskeletons in physical therapy.