Should I use a serif family for monospaced fonts?
The appropriate generic font family name for monospaced fonts is monospace. The fonts you have chosen do have serifs, their fixed width is the key aspect. Monaco, Courier and Courier New are quite common across platforms, but Lucida Console, Consolas and Lucida Typewriter are a closer match with Monaco on Windows. DejaVu Sans Mono, Bitstream Vera Sans Mono and Lucida Sans Typewriter would be suitable for Linux.