SVR 2009 Undertaker is the ideal base for Ministry Taker mods.
I remember that a long time ago, A member in this forum post a comparison pic between Undertaker SVR 2009 and Undertaker SVR 2010, And the comparison pic showed that SVR 2009 Undertaker's body build is more bulky than SVR 2010 Undertaker's body build. Since Ministry Undertaker's body build is more bulky than the current era Undertaker, I think you should use SVR 2009 Undertaker as the base for your Ministry Undertaker mods.
Anyway, This is just a suggestion. The choice is all yours.