Starting out, there's the M3 Stuart. This light tank saw combat all over the world. It fought against Japanese tanks on Pacific islands, German tanks in North Africa, and more Germans on the Russian steppes. It was reliable and rugged, praised for the smooth ride it provided crews.
The other kit available for pre-order is the M18 Hellcat platoon. This one you can get in a set of 3 tanks, or one with 2 tanks and an M20 Utility vehicle. This set also has some other additions to it, including stat cards and damage markers. Rather nice, those.
M3 Source
M18 Source