"The dude" wrote in message
I want to remove the carpet and replace with hardwood.

I have a few options.
Remove the existing floor up to the top of the stairs, and lay down all
new floor on the stair landing and the rooms.
Then I can put pre-finished floor without worrying too much about
matching.

Or I can put down unfinished and then refinish the entire upper floor.
Not sure about this one since it will be DIY.

Not knowing your skill level, it is difficult to recommend DIY unfinished
hardwood. You can rent the tools or buy them and re-sell after the job is
done. It takes more finesse to sand the floors than many people have. I
recall my first experience and leaving a couple of valleys.

Pre-finished is simple with a few tools that you will want to have anyway.
That is the way I'd go.