If you want a the toughest Emaxx you also want titanium skid plates. Great Assembly is the only place I know of with new ones, or you can hunt down the discontinued Hardcore Racing skids.

A more necessary upgrade is the hinge pins. Stock and Lunsford titanium hinge pins will bend, I've bent multiple sets. Getring bent hinge pins out of aluminum bulkheads is not fun. I haven't tried them, but FLM hinge pins are supposed to be about the best. Maybe BuggyBasher could chime in, I believe he's running them. The best is cutting your own hinge pins from ejector pins like the UE supermaxx guys do.