In short, yes. Yes HiRez can match SACD sound quality and yes you're wrong thinking that the "lossless stuff" in only for redbook CD.
Any computer with USB and a (preferably asynchronous and capable of more than 16/44) DAC will give you hirez audio playback.
Asynchronous USB is the best way to go computer-based, but it's not the only way.
New universal players, like OPPO BDP-95, can play hi-rez files directly from a hard drive, no computer needed. Since it also plays SACD, it will give you a good way to compare the SACD and hirez formats alone while keeping everything else the same.
Any computer with USB and a (preferably asynchronous and capable of more than 16/44) DAC will give you hirez audio playback.
Asynchronous USB is the best way to go computer-based, but it's not the only way.
New universal players, like OPPO BDP-95, can play hi-rez files directly from a hard drive, no computer needed. Since it also plays SACD, it will give you a good way to compare the SACD and hirez formats alone while keeping everything else the same.