You need to size your dehumidifier by the amount of water you feed per day. Like 99% of the water ends up transpiring from the leaves.
If you feed 200 pints a day on average get a 225+ pint system.
also I am the type of person who likes to split their risk. Let's say a dehumidifier fails. If you are running two smaller ones you can limp through with some dehumidification. If you only have the one larger one you are SOL in the case of a failure.
Are the floor models otherwise unused and come with the same warranty? it's a no brainer to me. You get more dehumidifying capacity, split your risk. I'd buy the two 180s.