Many types of downloaded music in various formats have sampling rates
that are higher than the 16/44.1 kHz that you refer to. Look at HDTRACKS,
ITRAX, PONO, 2L, Reference Recordings, Linn Records, Blue Coast
Records. Some of the downloads may even be DSD which is another
format. I could go on and on, but I won't as this may be an April Fools Troll!
You seem to be way behind the times when it comes to digital music and
downloading or streaming music. I suggest you do some reading and visit
computer audiophile.com among others to get up to speed.
If you only plan on using CDs as your media then you are fine with a DAC
that will only convert 16/44.1kHz.