Well, I don't have the same problems as you do but I think I might have a suggestion for you that could work for you.
First I would like to welcome you to the party.
Now what I've found is that a duct tape "outline" of your body helps with these things. If you've ever made a duct tape...
Re: UNSC army trooper foam build
Very cool. That's really smart to use something like that vest that is already made and not having to make something yourself. Besides I think that vest is going to add a lot more to the look of the armor once its all attached. Can't wait to see the finished look.