Hey there. The Peace lily is really a lovely plant. It grows well in shade or low light situations. The Croton requires a lot of sun. So that might cause some problems for you. If I was in Wisconsin and needed to make a choice it would be for the Peace Lily. It would have a much higher chance of making it in your care. The croton is going to tank it no matter what you do unless you have really superior indoor growing facilities.
If you have a problem keeping the Peace lily moist you might try double potting with vermiculite. Sandy

The Peace lily is a plant that likes warm temp too.

Croton will make a nice patio plant for the summer but will die with first sign of frost. Never heard of them being used as a pond plant. They are very difficult as houseplants, require constant humidity and are spider mite filet migon.

Spathiphyllums are usually really easy as houseplants if it needs water that often try repotting it. Mine only gets water once a week and it isn't wilting in between. It won't like frost either if you put it outside.

I'm with Sandy on the Peace Lily. I have three of them. Two are outside on a north-facing porch and because we're pretty hot here in the summer, I water them every day, and about once a week they get a dose of liquid fertilizer. The third is in a low light area in the house, and it is watered every two or three days. The hotter and sunnier their position is, the more they will need to be watered. I bring them all inside for the winter months. They do seem to need more water than some other plants, but I think they are worth the trouble. They are my favorite house plants.