Since I could not find a typography / font SX I figure this question might be suited best here (also I want to use the fonts for a LaTeX document).
I find the Gentium font visually attractive and I want to use it for my bachelor thesis. The one thing I'm wondering about is which sans-serif and monospace font match best (from a typographer's point of view) with Gentium. I'm thinking about setting the section titles etc. in serif, too -- that would lower the needs for a sans-serif counterpart. But a good typewriter font is needed anyway.