Most monitors will support VESA resolutions including 4:3 ones, but:
1) Don't limit yourself to BenQ, they have a few ok screens and a lot of garbage. Usually you can find an LG/Acer/Asus monitor for the same price with better overall quality.
2) Don't use strange resolutions unless absolutely necessary. It won't break your system, but if you're using a strange resolution you're likely doing something horribly wrong.