I think there will be two issues with that armor:
1) If you do it movie accurate, you need some kind of device to be able to control both legs and hands, considering that your hands will be kinda small for the size of the Igor
2) If you make it human size (screw movie accuracy) you still have something that isnt scaled to a normal sized human
Also, i think that the stability of the foam and the size of the parts are in inverse proportion, so, more foam, more problems.
Thats my un-educated guess considering that i never cut a single sheet of foam.
Sorry for spelling mistakes, im spanish speaker.