would suggest going the upgraded dac route... you have a really good transport...
it is really sad the high res formats didnt make it. hopefully they will continue to do them for the "philes"....
there was a really good post under " Reference DACS: An overall perspective..." that offered some good insight (the question is what sonic characterics are you looking for and what is your budget ?)
it would seem the benchmark is a great choice if you want a more "detailed" dac or the bel canto for a "warmer " sound..
though i am currently looking for a used dac myself (considering the muse 24/96, theta gen v, audio research dac 3,stello, audiologic(highly reguarded and reasonably priced), and electrocompient, audio aero etc...
btw, if you can afford it ( it is reasonably priced but more that what i can afford) the tube technologies gear is the most musical digital playback i have heard to date...