Toyota Corolla 98 Power steering replacement

Hello Sirs,

Good day po sa inyong lahat! Hihingi lang po sana ako ng recommendations regarding po sa pag palit ng worn out power steering assembly ng Toyota lovelife ko po. What would you recommend po?
1. Replacing it with a surplus unit?
2. Replacing it with a brand new / replacement unit but made in Taiwan?
3. Where can I get a good and reliable surplus unit?
4. Where can I get a good deal on a replacement / OEM unit?

Thank you po. All your recommendations will be highly appreciated.

Joeyvhoi