Thanks for the advice Sean. Always good to have another woodworker helping out on the site as there are plenty of questions needing opinions and points of view.
I have painted wood porches but there is the maintenance issue of repainting. I personally like carpet and not paint on an interior floor but that isn't for everyone. Like Jay J and others, I give my opinion as to how to proceed but then go on to offer advice on what they are asking, if I know, since it is their house and their nickel and ultimately their decision.
I think the issue Red and Jay J were talking about is not to put down an expensive wood if it is going to be painted anyway. So if he wants to paint, find the cheapest wood possible, even used wood. Keep wood filler and plenty of spare paint to touch up the dents and scratches. That said, a solid color stain may be better than paint as far as handling foot traffic and avoiding paint chips, etc. and may be easier to recoat each year. Go to your local paint store and talk to them. Maybe others have some better ideas.