These Common House Plants' Names?

I have acquired two beautiful rainforest foliage plants this week. One has long leaves with a semi dark green on the top of the leaves, and a brilliant purple on the underside. Also, another plant with long thin leaves like the one just mentioned, but it is green with the outer rim being a creamy white. I was wondering if anyone could help me find the names to these. I have spent a lot of time looking them on the internet and I'm not getting anywhere, so I must be looking in the wrong places. Thanks ahead for any help. :)