You can see each font on the screen and print what you see. I've been using its SuperFrench German Spanish for a little over two years and have had absolutely no problem with it. In addition to this font, Linguists' Software offers several more. MacTransliterator has a set of letters sufficient for 75 languages and includes 50 diacritical marks that can be used in combination with any letter. MacPhonetics is a font containing the International Phonetic Alphabet.
Tech is a font containing characters useful in mathematics, engineering and science.
Another company, Ecological Linguistics of Washington, D.C., has developed integrated sets of fonts, string-comparison resources, and keyboard desk accessories for dozens of languages. Each package comes installed in a System file. The second solution is changing the font. You can change one letter or symbol, add characters to a font or create an entirely new font. The program I've used is FONTastic from Altsys.