Here's a nicely done set of 54mm American Civil War Confederates from Timpo. The set contains ten figures in five poses and while it doesn't include a horse for the Officer figure, I put him on an Americana steed and it worked quite well - at least he didn't fall off! Enjoy!
Officer with Sword Drawn
Advancing Rifle at Side
Standing Firing Pistol 1st Pose
Standing Firing Pistol 2nd Pose
Standing Firing Rifle