9.26 for the Helmet worked perfect for me but I'm 6ft even. I based it on NAS dimensions so it should still work well for you.
I haven't hammered down the rest for me yet but 28 seemed just about perfect on my test piece. Just measure the height of the piece based on your own dimensions (for forearm use wrist to elbow +3 cm etc.)
I thought about dividing up the pieces but the polys dont match with the plate boundaries so... :Steve:
I did do it for the helmet though, left a bit of overlap in the back so it would still be clear where everything goes. You might choose to cut off part of it.