#1 Take your entire stock harness out and put it in a box. forget about it. dont try to duplicate anything the factory did.
#2 Use the chevy wiper switch and hi/low beam switch. they fit in the factory dash and wiper switch hole. this allows you to use the chevy plugs that come with the kits. (your original plugs are most likely shot and thats why your replacing them)
#3 No matter what steering column you end up using. cut the factory plug off and use a molex style plug or another to your liking. they are better quality and just make everything easier.
#4 if you have the dash mounted ignition CAREFULLY take apart the factory plug and you can reuse it.