Okay, I just did a quick bit of research for those two varieties based on the sites I have bookmarked. I would say
Northern Tropics will be the cheapest, but I'm not entirely sure what their shipping is, or if they have a minimum order. Another site that has good deals on those varieties is
Green Earth. You can get both plants, plus shipping for $31. The main advantage of Green Earth over Northern Tropics is that you will receive 14" plants rather than 5" plants. Just something to think about if you want to get growing fast. I've purchased a few plants from GE and they have great prices and reliable service.
Hope that helps out!