Btu rating for stone deck bakers pride

I’m new here so please excuse me if this has been answered elsewhere. I’m shopping for a deck oven for a new shop. Bakers pride has models from 70k btu -120k/ deck.
I do 60% hydration , 3 day cold fermented dough with oil & seed it with a biga.
I usually run the deck & top element at 500. I have a old bread oven currently. No idea how many BTU’s My old oven is or what I would need for my new store. Any help is welcomed and appreciated. Thank you.