proportional fonts

matching fonts for line spacing


Are any two fonts (that are NOT monospaced) known to be matched in terms of the width of every glyph? I mean one that is serif, and the other is sans-serif.

My goal is not to pair or match fonts for aesthetics and use them together, but to find two that are interchangeable without having a single glyph need more or less space. If I need to purchase fonts, realize I'm on a schoolteacher budget but the investment would be worth it.