If your specifically looking for a German tank in 1941, and Tamiya is your only choice, then probably the Panzer II. They have an older E/F that is toyish and a new C that could work, but I'm not sure about decals.
They have a Panzer III L, that came out I think in 1942. The StuG III G early I'm thinking around the same time.
However, if Tamiya isn't the game, then a Dragon Panzer III G has the decals and jerry cans for Africa. They also have a J which I think fits the time frame. They also have shorter barreled Pz III E-F and Pz IV E-F. The E again is set up for Africa.