Another vote for Lasalle. An easy game system to begin playing the period. My current club use Shako, which are quick and easy, and only need 18 figs per unit. They needed a bit of modification, and the order system inspired by that in Napoleon’s Battles made it a playable set of rules. If you want to use a bit more brainpower, then Gen de Brig is a very popular set in 28mm if you dont mind buying and painting 36 and 40 man units.