Waterproof paint above tub w/ shower?
Here's the facts: Very small budget, on Social Security. 90 year old house, plaster/lathe walls. Inset tub area has 2' good tile above it, then ugly vinyl wallpaper to the ceiling. Probably oil based paint underneath. I have used a handheld shower and hung clear plastic shower curtain in front of (but not clinging to) the walls for 7 years, no damage I can see. Shower used 1-2x/week, dries quickly.
Now I want to paint the whole bathroom, using waterproof paint in the tub area. Here are options I'm considering:
1) Valspar Ultra Premium OIL-BASED Int/Ext Porch/Floor Enamel which is polyurethane-fortified high-gloss. (I'm leaning toward this one)
2) I have used Zinsser Water Tite on my basement walls with good results. It says it's for concrete but would it work over the plaster wall?
3) A local paint counter person also suggested "maybe" epoxy paint would work, Valspar epoxy clear-coat made for over concrete.
It's just me in the house, and I need to DIY. I expect to live here another 15-20 years.