I bought the mud flaps from Ford, went to the dealer and ordered them. I looked up all the accessories I wanted on fordaccessoriesstore.com, grabbed the product #'s and said "these are what I want". Came in a couple days later.
The bug shield wasn't too difficult to install, the instructions were terrible but if you've ever installed one before you can figure out where everything goes easy enough.. just make sure you measure 5 times and drill holes once!
I'm in a bad area for road salt too, but as for drilling holes to put the mud flaps on you drill into plastic... so rusting wouldn't be an issue, and the screw/clips you put into the holes you drill are plastic as well. The only place I had to drill into metal was the hood for the bug shield.
Again, thanks for all the kind words everybody!