Bead chain. The problem with paracord is with a 550lb test you will choke to death before that cord breaks. You could catch it on something or someone could use it to choke. Yes, very very very unlikely but still...
One thing I have done with the two neck knives I actually use as neck knives on occasion is hollow out the paracord and run part of the chain through it so you still have access to the chain. The chain is holding the knife on but you get the look and feel of the paracord. Don't if that made sense. Found out about the idea on here. I'll post up some pics later if I remember.