W211 Spark Plug and Wire Replacement

I am getting ready to replace the valve cover gaskets (leaking) on my 2003 Mercedes E320 with 160k miles on it.  Since I don't know the service history of the vehicle, I was going to replace the spark plugs at the same time since I'll already be working in the area.  Should I also replace the spark plug wires?  They look to still be original but I do not know for sure.  And what about the ignition coils?  Should I replace those also?  The car is not currently misfiring or anything.