My favorite rules for tactical Napoleonics are "General de Brigade" by Dave Brown. They have enough chewiness to satisfy me while still moving quickly.
They are also well supported with official scenarios. The book "The Glory Years" contains three scenarios for Austerlitz, and one has the famous charge of the French guard cavalry. The scenario calls for 20 Chasseurs a Cheval and 32 Grenadiers a Cheval.
All figures are AB Miniatures, bases from Litko, and flags from GMB.
Guard Chasseurs a Cheval
Guard Horse Grenadiers