For ACW, I use my own house rules. They started out as a small addition to Brother Against Brother, but now have morphed in such a way they are barely recognizable.
My rules are hex-based, one unit per hex. Hexes are 10cm across (Kallistra), 28mm figures. Also unit-based, so no need for individual figure removal. I use 12 infantry figures per unit, or 6 cavalry figures. Generals are individual figures. Artillery is 1 gun + crew.
Tiny Tin Men Blog: http://snv-ttm.blogspot.com/
Wargaming Mechanics Blog: http://wargaming-mechanics.blogspot.com/