Character pipe lineing

I have a character in blender and I have several parts,Chest piece, scarf etc.I need to add collision and all.
Should I just rig the body first, get it into ue4 and then add all the pieces using the different bone set up in ue4?? I’m not really sure what I need to do first.

Also I have to add collision to clothing use Nivida, there are several parts that need this collision on them, where do I start?? after have a character and all the parts done.Can someone help me with a good pipeline to get a character ready for in the world test and final animations.