Which DAC from this list sounds best with my system: Atoll, Micromega, PS Audio, Simaudio?

I currently own a Cambridge DacMagic (original) and I'm using it with a Sonos Connect Network Streamer. the rest of my system consists of a Roksan Kandy MkIII integrated amp and Vandersteen 2C speakers. All cabling (RCA & Speaker) is Mogami.

I'm using the Digital-Out (Coax) from the Sonos to the DacMagic. Then from there to the Roksan. I like the sound of the DacMagic, but I'm looking for something that has a little more impact or slam (dynamics), as well as better bass definition and response. Perhaps something a little fuller in the mids too. 

Here are the DAC's I am curious about/considering:
1. Atoll DAC-100
2. Micromega MyDAC
3. PS Audio Digital Link III
4. Simaudio 100D

If more bass is what you are after I would suggest getting a bluesound node 2. I tried many dacs with my Sonos looking for improvements and finally settled on a node2. Much better bass slam. If you like the Sonos interface then perhaps try a reclocker first or get the Cullen mods performed on your Sonos before spending a considerable amount of money on a dac.
The only reason I have the Sonos is so I can get Deezer HiFi, which is their FLAC streaming service. It's exclusive through Sonos and for those using a desktop, which I am not. Is Deezer HiFi available through bluesound? 
the Sonos sound quakity is limited, but I had best luck with Parasound Zdac...
There is a Metrum Pavane and Hex DAC for sale here now, and I'd think either would achieve your stated goals and in general be a huge improvement over your current DAC.  Best of luck. 

If I would sell the Sonos and get a Bluesound Node 2, do you think I would feel the need to get an external DAC?

Thanks for all the suggestions so far. I should have given my budget as some of the offerings are out of my range. My budget is $300-$500 max. I’m looking at used obviously. Another DAC I wanted to add is the Benchmark DAC-1. Any good?

As of now, gmy budget, I’m thinking either PS Audio DLIII, Atoll DAC100, or sell the Sonos and go Bluesound Node 2. 
Quick question: Has anyone ever compared the Micromega MyDAC to the PS Audio Digital Link III (stock)?

If so, what were your impressions?