As noted elsewhere, I am re-doing a second floor apartment that a tenant
just moved out of.

Unfortunately, the previous tenant had cats and there are cat urine stains
everywhere on the existing old hardwood floors. There were rugs on top of
the old hardwood floors, but the urine stains went through the rugs to the
hardwood floors. So, barring some miracle way of getting rid of lots of cat
urine stains and smell, it looks like I am going to have to rip up the
existing old hardwood floors to get rid of the smell.

If I go that route, I want to put new 3/4-inch hardwood down -- not Pergo,
laminate, vinyl, etc.

My questions are related to what type of hardwood to get.

I was thinking of maybe putting down pre-finished 3/4-inch hardwood -- such
as Bruce prefinished hardwood. But, my concern about that is that the
prefinished "colors" are apparently a stain and finish -- so if the floor
gets scratched or damaged in the future (hopefully not by cat urine), I
would need to sand out the damaged area and then have to figure out how to
match the stain so the color would match. Instead, I was wondering if there
is some particular type of finished or unfinished hardwood floor that would
look good with just a clear polyurethane finish. That way, to repair any
damage, I could sand it out and apply a clear finish again and hopefully
that would match the original finish.

If I go with that approach, is there any particular type of hardwood
flooring that I should consider getting -- oak, maple, something else? --
either finished or unfinished?