I would strongly recommend the Funk LPAs (even if it has to be sent quite a distance).
Funk Tonstudiotechnik digitale und analoge Tontechnik index
http://www.funk-tonstudiotechnik.de/LPA-2-englisch.pdf
You won't find that good specs anywhere else - and you know what your money is for (NOT unnecessary big casings or the like..). (i'm not involved in any way, but his products definetely needs more recognition). I exchanged the Headphone Amp in my Tascam DA3000 with great success.