It sounds like you could go practically any direction on this but you might consider planting a plant that likes a similar amount of water or sun. Past those considerations, I think the sky's the limit. Actually, once you hang the basket, how much growing height space will there be for the plant in the pot? That might also help you decide.

I was reading on companion planting and it said do not plant strawberries with cabbage, beans, or broccoli

Did your source give any valid reasons? Basically strawberries are a perennial which will be in position for several years. Cabbage, beans and broccoli need to be planted every year and require cultivation of the soil. That alone means they are not a good choice for putting in a strawberry bed. I would not plant anything else in a container with strawberries. They need all the nutrients, water and space they can get and don't need any competition.

Thanks all, but it's a moot point. They are in a large container, by themselves, and I have been busy eating the first harvest.