What fonts & packages would you recommend for a project in XeLaTeX that requires:
- serif font (Latin script + French, German, Spanish, and Polish diacritics) with small caps support,
- math font that in addition to standard / simple equations supports Greek letters (upper and lowercase + their bold versions for vectors or matrices) - so no 'real math' ;P,
- sans-serif font (Latin script + French diacritics),
- typewriter font to typeset some source code.
I did check: LaTeX font catalogue http://www.tug.dk/FontCatalogue/, GUST resources (e.g. http://www.gust.org.pl/projects/e-foundry/tg-math or http://www.gust.org.pl/projects/e-foundry/tg-math/gust_e-foundry-math_fonts-presentation.pdf) and read some related questions like: State of Unicode math typesetting fonts?, What are all the font styles I can use in math mode? or How to use system font for equation in XeLaTeX?. But 1) the answers are about 2 / 3 years old and it changes quickly and 2) I'm interested in current, informed recommendations (I can only pick sth that looks nice and experiment).