This thread made me go buy the newer Tiller game Battle For Normandy. It's good and is like all his other games pretty much, same GUI, etc. Me and his games go back to the Talonsoft Battleground series, which you can also get at Matrixgames. I have both the Napoleonic and Civil War series.
Then there is HPS that also sell these types of games.
http://www.hpssims.com/