From my experience of breaking ribs it aint pretty, though i did get farely f*cked up. Broke two ribs(10th,11th) right next to my spine. Bruised the core muscles that run up your spine aswell as bruising my spine,kidney and lung. The healing process is 4 weeks behind shedule. They only started to unite 2 months after breaking. But that's just me and how i got hurt.
Now i'd shy away from hard plastics because i'd presume they would push into you and only really protect against the skin breaking where as padding should you know, help against brusing as well as all the other stuff. Thus why i suggest the 661 kore suite as it is designed to protect the interals.