For good translation you need some one who is fluent in both languages and fluent in the technical domain you want translated and is skilled at translation. You

For good translation you need some one who is fluent in both languages and fluent in the technical domain you want translated and is skilled at translation. You're asking for skilled labor at the intersection of 2-4 different skills (depending on how you count it) and depending on the domain one of those skills might already be pretty rare.