If Matt decides to go with WWI, I would like to see him do the 1916-1918 time period. Both Britians and King and Country have been concentrating on the beginning of the war. 1916 saw the introduction of steel helmets by France, Germany and Britain, and gave us the major blood-lettings of the Somme and Verdun.
I will put in another pitch for the War of 1812, particularly the Battle of New Orleans. Right now only John Jenkins is touching the war and only the Battle of Chippawa. New Orleans has tremendous potential for variety (regulars, highlanders, riflemen, Marines on both sides, Naval gunners, field artillery, rocket toops, local militia, pirates) , and with the bicentennial of the war, couldn't be more timely.
I also wouldn't mind seeing Agincourt, or Naseby, or Culloden, or Breitenfeld, or Balaclava.