>>269888782
We usually just use the base game and the Japanese Pack, but the Ultimate Edition is worth getting if you know you're going to want all of the DLC.
Also, for anyone who's interested, Assetto Corsa is apparently on sale on Steam right now.
$5 for the base game, $17 for Ultimate
https://store.steampowered.com/app/244210/Assetto_Corsa/