Apart from the obvious difference in its winter camo the only real difference between a Western Front and an Eastern Front PZ4 is the winter tracks and those are available as an upgrade,
I bought a Heng Long Body and a Taigen metal hull with snow tracks and 4-1 gearboxes and a upgraded Taigen Turret separately (The Taigen Quick Release works with the Heng Long Body) and after a little work on the body I finished it off with a winter camo finish and lo and behold a Panzer 4 Ausf G on the Eastern Front,
You can be anywhere in the World and if you have access to a Post office you can buy the parts on line and the postage will be far more bearable than buying a RTR Tank .
Have you thought of using Banggood or Ali-Baba as a source ?