50 gallon help?

I am hopefully going to start a 50 gallon tank rescape. This is at an assisted living place that my sister runs. Seeing as she has no budget for that type of thing, I was wondering if people would be willing to donate stuff. It would be tax deductible since this place is a non-profit organization...

Now after that, I need recommendations for low-maintenance plants, and a good type of schooling fish.
A design that is peaceful and inviting seeing as many of the residents don't quite have the mental capacity for anything too complex.

any advice would be greatly appreciated, thank you!