/cgl/ - Cosplay & EGL

So figured this would be faster replies than the regular help thread. cgl regular so don't worry about skill level and time, it's also not specifically for Halloween but if I finish before then it would be nice.

I'm trying to make my bf an Alphonse Elric armour. He's a big guy, 180cm with a few back and shoulder problems, one of his shoulder joints dislocated last year and he has back pain. I'm making the armour out of craft foam so weight isn't a problem. However I want to keep the scale accurate which is something that irks me about every Alphonse armour I've seen. The shoulders aren't wide enough and the head is too big. I'm planning to have him see out of the collar/neck part of the costume so the head and height can be accurate. However this means the shoulders are going to be too high up for his regular arms. This is his silhouette next to 2 references. How can I help make it accurate but still keep it relatively comfortable for him to wear? I thought about fake arms like in Space Marine/Big Daddy suits but it's not big enough, and I've never built anything like that before. Also I'm worried it would look bad in terms of posing and added weight.