Originally Posted by the_bird
Perfectly fine with either. There's no hop character to a dopplebock, just a bit of bitterness to offset the sweetness, so I'm assuming the recipe only has a 60 minute addition. I'd probably go with the Tettnang, but either would be fine.
Even if it was supposed to have a hop character, I think the recommended replacements for haller would be tett/saaz anyway.
Just make sure to get your IBUs right.