Spectral is a parametric serif font with true italic, bold and small caps, a number of weights, and the desired Latin Extended Additional diacritics. It’s free to download and is available for use under the SIL Open Font license 1.1. Personal take: Spectral is a big advance on what’s out there, offering unprecedented typesetting flexibility, but it’s not yet clear how well it is suited for the printed page. See some informed criticism.
git: https://github.com/productiontype/Spectral
