OK so I have this old house....
I have about 900 sq feet of floor space that I want to put down pine flooring.
The floor currently has either carpet or oak hardwood.

I see ads for heart of pine, yellow pine, red pine, old pine, rustic pine, etc etc etc.

What about the No 2 Pine boards that Home Depot or Lowes carries. Could I use those with a router table to put the mortise and tendon on so they fit together? Is there a reason NOT to do this? Are there wear differences between the differences in the pine boards that I can see\read about on the web?

The house is a old mountain house that I wnat to keep looking rustic but I want to warm it up with pine floorings.

Thanks in advance!