Advice needed for intergrated fridge freezer

Hi
Just need some help I'm moving into a new property next week. I will be getting a new kitchen fitted in a few months. But I need to get a fridge freezer now as I want it intergrated when the kitchen is renavated.
So I want to know does the size of the fridge freezer matter when it comes to finding a unit to house it?
I don't want to get a fridge freezer and not be able to get unit to house it depend on where I buy my units from.