The rules I am currently using are Big Napoleonic Battles: here and QR sheet. These grew out of Bloody Big Battles, and retain their core mechanism, but much else has been modified to give a game that feels more Napoleonic than the original, designed for wars 50 years later. Units of typically four bases represent divisions, and a turn represents an hour. These rules are pared down and give a good multi-player club game. with units representing divisions.
Meanwhile here are the rules that I developed for the Vitoria game in 2013. These produce a longer game with half-hourly turns and brigade-sized units. Here is the latest version of the rules: 2.02: DTN V2-02 and an accompanying quick reference sheet DTN V2-02 QR. Version 2.02 of the rules is a development of V2.01 (!) with which we staged our Vitoria refight. It makes quite a few significant tweaks, but it is of fundamentally the same design.