Think at that price (and even higher) you may have problems finding SACD.Thiunk that may folks will reccomend at this price Perpetual DAC and it's PS.Think you can get them upgrated from a number of sources but underwood wally say's hjis have been approved by manufacturer and won't void warranty.Not sure if you ned Toslink or other types of inputs but again at the price you may be limited.I expoect down line fire wire or HDMI (though this may just be video stadard now)expect some sort of "fast" transfer will be come standardbut no new standard has become ubiquitous beyond optical and stanbdard RCA digital out.
Chazz
Chazz