How do I get a floor with this amount of color variation? is it just a product of these particular species and finishes? in that case what species/color provides that amount of color variation? or is it some type of special order? or were different colors ordered and then mixed up when installed?

I have been to 2 different Home Depot's, Lumber Liquidators, and Lowes and have not seen anything like that displayed on their 2 x 2 display panels. Is that just because the more uniform look is more desired?

thanks

Color variation as in your pictures is very common, and available where you mentioned. What your seeing in the "2x2' samples is not a good representation of what your entire floor will look like. They usually use 2 , sometimes 3 planks to make up the sample. Also depends on which tone of planks they use to make up the sample. Personally I would go with a local Hardwood Flooring Dealer.

Look at some natural hickory or tiger wood if you want lots of color variation