I like your idea. I've only seen the traveling Wall, never been to DC. Even the traveling wall chokes one up.
The one thing I've always said is that the Wall in D.C. is in the wrong place -- it should be away from all the other monuments (perhaps in or next to Arlington Cemetery). While it honors the 58,000+ who gave their lives in Vietnam, it also represents one of the most shameful eras in our nation's history.
I don't think Abraham Lincoln would be too proud to look out upon it from his seat in the Lincoln Memorial, knowing how this great nation of his had p!ssed away so many lives and wasted so much courage and heroism like that.