DIYbanter - Bathtub install questions

We are in the beginning process of remodeling our small family bathroom. We
are swiching out the cabinet style sink w/ a pedestal, putting in a new one
piece toilet and ripping out the old floor (Including sub floor).
Right now I'm trying to figure out what to do w/ the bathtub/shower.
Structurally the tub is sound, however it's about 60 years old. It's
chipped and dirty no matter how much I clean it. There are flat white
ceramic tile in the surround that are in good shape but for the mold issues
in the grout.
My choices seem to be:
leave the tub and surround as is (the worst choice)
Have Rebath or something like that, come in and put a new coating over the
surround and the tub.
Having a new tub and surround installed (from a kit)
New tub and ceramic tile (but I'm worried about mold in the grout again)

I really have no idea what the best thing to do would be. We are trying to
do this as economically as we can.
Any thoughts or ideas?