My 1989 Hi Lo has oxidized paint and I want to repaint it. I'm not sure what kind of paint to buy.

Yes you can, I repainted my 1982 funlite about 15 years ago I used auto paint and taped and sprayed it on just like painting a car. I changed the color's instead of the HiLo brown's I painted it 3 shades of black repainted the toung black and all my hitch equipment. Looked grate I increased the value when I sold I got $4000.00 above book price.
Sam