Honestly, i dont think that suit would have lasted long, looks way to unmanuverable and bulky. Spartans pretty much wear tank armor, the only reason why a nuke reactor is needed is to power the shields and life support, its not a much of a Iron Man suit, the Spartans are the only people big enough, and strong enough to deal with the wieght of the armor.
Believe it or not, when guns started being introduced, way back when, knights and such, needed stronger armor, Blacksmiths did that and acctualy made them bullet proof chest pieces that was pretty much tank armor, if i remeber corrrectly, 2 metals layered one on top off the the other. Progress my firend, something that there has not bee much off, because the need for a "human" soldier is declining and the need for termenators, as a example, are going higher. Even though i would love to make a operational battle suit, wheather a Mk 6, Iron Man, VS or heck a Gundam, i don't have money or resources, even though i hope one day i do, lol, dreams of young future engineer.