southern pine flooring
I have lived in several houses that had yellow pine flooring, all of it rather old. Yes it is a soft wood, especially compared with maple or oak, which is in my current house. Old yellow pine is still available, it may be a little pricey, but you can get wide boards. I don't know if you can easily obtain wide yellow pine from newly cut trees. I believe installation is done the same as with oak, typically nails or staples. The finish may be different, all of my floors have been varnished, but there are all sorts of alternatives available, none of which I have personal experience with. Perhaps one of the floor installers here can comment.