Best DAC Mac Mini with HUGE soundstage?

There is no definitive "best" of anything. There are way too many variables involved. The "best" you can hope for is to find something that works well in your system. You can then say it's the "best" for you until you find something you think is better !!!!

True, but all things being equal, some dacs are reported to deal to work better with digital feed from a mac than say a cd player and some present a thin soundstage and others a bigger one.

Anyone have any suggestions?

Get a used Eastern Electric or Metrum Octave.

haven't heard it yet, but in that price range, I'd definitely want to check out the new Schiit Gungnir. I'm using a Wadia 121, which is a slightly above your price point, but not much. I like it a lot.