I have never had any problems with the existing spritefont plugin. It's also important to note that most font's have licences that restrict you from re-distributing them.
With the existing spritefont plugin you can easily have multiple languages because any character in any order can have it's own image made by you. You just set in what order each character will be read.
!"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz