Gaijin should seriously consider the following vehicles:
T-34-85 (1969)
SU-100 (1969)
T-44M/MS
ISU-152K/M
IS-2M
IS-3M
These are all Cold War modernizations of otherwise WW2 Soviet tanks. They come with improved engines with higher horsepower and in most cases HEAT ammunition. I will do a massive post on it once all of my suggestions get published.