The sample cards are good but imo you will get a much better idea of the paint if you buy small samples and paint 1' square patches on 3 or 4 different walls so that you can see the paint colors in different parts of the house and with different light. The house you linked to has a lot of windows in the public living space and your color will look different in different parts of the room.
I would do the floors first and paint second. If you're sanding during the staining and sealing process, you don't want all the dust messing up your paint. Yes, painting second is a pita for the painters. Ask me if that is my first concern ...