Money is an issue but I can spend $4000 or so which I think should do the
job nicely.

That might buy the materials, but no labor. I agree with another poster that
your budget is way low. Things like floor reinforcement may add a bunch, and
the list keeps growing, the more you get into it. Bathroom renovations run
second only to kitchen redos, which are typically in the $15K range.
Go ahead and do whatever you like and good luck finding a quality-minded
contractor to work with. When it's done let us know if $6-7K got you what you
liked. HTH

Joe