I find it really depends. did you have a strong early game leading up into the mid game, where you held your own fuel for the entire/majority of the time and held a decent portion of the map? consider going for a quick Ostwind or a panzer 4 to seal the game.
did you and your opponent have a bit of a stalemate where no side has a clear advantage? depending on your commander loadout, you can either stall for tiger like you touched on in the original post, or even going into panzer 4s isn't a bad idea.
did you make some mistakes and are playing from behind? get a pak or two and try to claw your way back into the game.
also, remember to lay down at least one teller mine in the early game. mines win games, and if your opponent is lazy about sweeping (or at lower skill games, completely ignores buying them) you can completely swing the momentum in your favor. managing your resources as Ostheer is important. LMG42s are amazing weapons, as are the aforementioned teller mines. Stug Es are also extremely potent weapons to have, and a tiger for the late game.
hope that helps
